[Amended] Material event report (merger)

What happened

Material Event Report (Decision to Merge Companies) 6.2 Rftech Co., Ltd. Amendment Report (Filing) - July 28, 2026

1. Disclosure document being amended: Material event report (decision to merge companies) 2. Original filing date of the disclosure document being amended: April 13, 2026 3. Amendment details - Item: 5. Basis for calculating the merger ratio; Reason: simple clerical error Before: (b) Merger value of common shares of Eco Volt Co., Ltd., the company being dissolved - Eco Volt Co., Ltd. reference share price: KRW 766 After: (b) Merger value of common shares of Eco Volt Co., Ltd., the company being dissolved - Eco Volt Co., Ltd. reference share price: KRW 773

Material event report / Matters subject to KRX reporting obligations To: Financial Services Commission / Korea Exchange July 28, 2026 Company name: Rftech Co., Ltd. Representative Director: Cho Kyung-sook Head office: 60 Jukyangdae-ro 1763beon-gil, Wonsam-myeon, Cheoin-gu, Yongin-si, Gyeonggi-do Phone: 070-5126-0139 Website: http://www.rftech.co.kr Preparer: (Title) Disclosure officer (Name) Ko Dae-ui (Phone) 070-5126-0139

Decision to Merge Companies

1. Merger method Rftech Co., Ltd. will absorb-merge Eco Volt Co., Ltd. - Surviving company: Rftech Co., Ltd. - Dissolved company: Eco Volt Co., Ltd. * Name of the surviving company after the merger: Rftech Co., Ltd. - Merger type: not applicable

2. Purpose of the merger Through this merger, the Company aims to move away from its current heavy reliance on a concentrated customer base in the mobile-phone components business and the volatility risk of upstream industries, by focusing on developing 5G communication technology for AI applications, building a full lineup of 5G antennas and filters, and entering RU filter mass production, growing this into the Company's core competency business going forward. Funds secured through the merger will enable stable R&D and high-value-added product manufacturing without external borrowing, enhancing the Company's long-term value.

3. Material effects and impact of the merger 1) Impact on management: The surviving company is Rftech Co., Ltd.; the dissolved company is Eco Volt Co., Ltd. As of the securities registration statement filing date, Rftech Co., Ltd.'s largest shareholder is Osung Advanced Materials Co., Ltd., holding 30.46% (combined with related parties, 39.95%). Eco Volt Co., Ltd.'s largest shareholder is also Osung Advanced Materials Co., Ltd., holding 29.89% (combined with related parties, 29.94%). After the merger, Rftech's largest-shareholder stake is expected to change from 30.46% to 30.29%, with no change of largest shareholder; the combined stake of the largest shareholder and related parties is expected to become 36.82%.

2) Impact on finances: Rftech Co., Ltd. (IT mobile components and telecom equipment) will merge with Eco Volt Co., Ltd. (automotive lighting modules and parts). The companies expect cost savings through integrated restructuring of the IT and automotive-parts businesses and improved management efficiency and scale from unifying the business entity. Amid stagnation in the smartphone end-market and a rapidly changing mobility industry, cost competitiveness through scale and advanced technology are essential survival conditions for the parts business. The merger is expected to consolidate dispersed overseas production bases (including Vietnam), personnel and technology resources, eliminating redundant costs and improving operating efficiency. In the short term, integrating similar manufacturing processes and joint purchasing of materials is expected to reduce fixed operating costs and the cost-of-sales ratio immediately; unifying management organizations is also expected to improve company-wide profit structure.

After the merger, Rftech's Yongin plant equipment and personnel will relocate to Eco Volt's Asan business site, improving plant and organizational efficiency, and the Company expects to secure additional cash-equivalent assets by selling the Yongin plant. Eco Volt's Vietnamese subsidiary SF INNOTEK VINA CO.,LTD is currently being sold; consolidating overseas production entities is expected to immediately remove duplicate costs and allow reinvestment of sale proceeds.

In the medium to long term, the Company plans to expand investment in next-generation communication technology using combined R&D resources and financial capacity. Specifically, the next-generation communication technology Rftech intends to pursue after the merger is RF modules for wireless communication infrastructure that handle increased network traffic from the spread of AI services. AI services require low-latency, high-capacity, highly reliable wireless networks for large-volume data transmission, real-time inference, edge computing, industrial automation, and autonomous driving/robots/smart factories, increasing demand for base-station antennas, beamforming (massive MIMO antennas), filters, and RF front-end performance. Rftech plans to focus technology development investment on supplying 5G Advanced/6G wireless communication infrastructure components for this trend. R&D personnel and costs are expected to increase accordingly, but the Company judges this will positively affect sales growth and profitability through successful entry into a high-value-added business. Overall, the merger is expected to have a positive mid-to-long-term effect on the merging companies' financial structure, sales and profitability.

4. Merger ratio Rftech Co., Ltd. : Eco Volt Co., Ltd. = 1 : 0.2027268 The reference share price for the merger ratio was calculated by arithmetically averaging the weighted average closing price for the most recent one month, the most recent one week, and the most recent closing price, using the day before the board resolution date as the base date, then reflecting completion of Rftech's par-value consolidation and Eco Volt's par-value split and capital reduction without compensation to derive the final merger value and ratio. - For a merger involving dissolution of a special purpose acquisition company: not applicable

5. Basis for calculating the merger ratio Because this merger is between two companies listed on KOSDAQ, pursuant to Article 176-5, Paragraph 1, Item 1 of the Enforcement Decree of the Financial Investment Services and Capital Markets Act, the reference share price for common shares was calculated, after which the amount reflecting the surviving company's par-value consolidation (par value KRW 500 -> KRW 2,500) and the dissolved company's stock split (par value KRW 1,000 -> KRW 500) and capital reduction without compensation (reduction ratio: 80.0%) was used as the final merger value to calculate the merger ratio.

(a) Merger value of Rftech Co., Ltd. common shares Base date April 12, 2026 (the day before the earlier of the board resolution date, April 13, 2026, and the merger agreement date, April 13, 2026): - 1-month weighted average closing price (March 13 - April 12, 2026): KRW 1,819 - 1-week weighted average closing price (April 6 - April 12, 2026): KRW 1,892 - Most recent closing price (April 10, 2026): KRW 2,010 - Rftech reference share price: KRW 1,907 - Reference price after par-value consolidation: KRW 9,535 - Merger value: KRW 9,535 No premium or discount was applied.

(b) Merger value of Eco Volt Co., Ltd. common shares Same base date: - 1-month weighted average closing price (March 13 - April 12, 2026): KRW 788 - 1-week weighted average closing price (April 6 - April 12, 2026): KRW 766 - Most recent closing price (April 10, 2026): KRW 766 - Eco Volt reference share price: KRW 773 - Reference price after stock split: KRW 386.5 - Reference price after capital reduction without compensation: KRW 1,932.5 - Eco Volt merger value: KRW 1,933 No premium or discount was applied.

Merger ratio accordingly determined: 1 : 0.2027268 (Rftech : Eco Volt). - Entity value: surviving company - not disclosed; dissolved company - not disclosed

6. External valuation: Not applicable - Basis and reason: Because this is a merger between two KOSDAQ-listed companies, the merger value was calculated and the ratio derived under Article 165-4 of the Financial Investment Services and Capital Markets Act and Article 176-5, Paragraph 1, Item 1 of its Enforcement Decree, so an external valuation institution's appraisal was not required.

7. Type and number of new merger shares: common shares 4,111,636; class shares: none

8. Merger counterparty Company name: Eco Volt Co., Ltd. Main business: manufacture of new automotive parts Relationship: affiliated company Financial details for the most recent fiscal year (KRW): total assets 253,843,277,165; capital stock 70,784,607,000; total liabilities 37,215,797,837; sales 217,426,570,735; total equity 216,627,479,328; net income -24,908,902,623 External audit: Taeil Accounting Corporation, opinion: unqualified

9. Newly incorporated merger company: not applicable

10. Merger schedule Merger agreement date: April 13, 2026; shareholder record date: June 30, 2026; period for receiving notices of dissent: August 6 - August 28, 2026; expected shareholders' meeting: August 31, 2026; appraisal rights exercise period: August 31 - September 21, 2026; creditor objection period: September 1 - October 2, 2026; merger effective date: October 3, 2026; expected merger registration date: October 16, 2026; expected new-share listing date: October 29, 2026.

11. Backdoor listing: Not applicable 12. Backdoor-listing requirement for another company: Not applicable

13. Matters concerning appraisal rights Exercise requirements: pursuant to Article 522-3 of the Commercial Act and Article 165-5 of the Financial Investment Services and Capital Markets Act, a shareholder registered as of the record date who notifies the Company in writing of opposition to the merger resolution by the day before the shareholders' meeting may, within 20 days of the resolution date, request purchase of some or all of the shares held in writing. Appraisal rights apply only to shares proven held before disclosure of the board resolution (or acquired by the next business day under limited exceptions) and continuously held until exercise; rights lapse for shares sold and reacquired in that period and cannot be withdrawn once exercised. A shareholder who notified dissent but then votes for the merger loses appraisal rights. As both merging companies are listed, the purchase must occur within one month after the exercise period ends.

Expected purchase price: KRW 9,325 Method of dissent: written notice to the Company (or, for beneficial shareholders, to the relevant securities company) by 3 business days before the shareholders' meeting (August 26, 2026); securities companies must notify the Korea Securities Depository by 2 business days before the meeting (August 27, 2026); the Depository notifies the Company by 1 business day before the meeting (August 28, 2026). Method of requesting purchase: written request stating share type and number within 20 days of the resolution date; beneficial shareholders file through their securities company, which must request purchase by 2 business days before the exercise period ends (September 17, 2026). Place of receipt: Rftech Co., Ltd. (surviving company) - 60 Jukyangdae-ro 1763beon-gil, Wonsam-myeon, Cheoin-gu, Yongin-si, Gyeonggi-do; Eco Volt Co., Ltd. (dissolved company) - 433-31 Sandong-ro, Eumbong-myeon, Asan-si, Chungcheongnam-do. Request period: dissent notice period August 6 - August 28, 2026; shareholders' meeting August 31, 2026; appraisal rights exercise period August 31 - September 21, 2026.

Payment: special (registered) shareholders are paid by bank transfer to the account they register; general (beneficial) shareholders are paid via their securities company account. Expected payment date for both Rftech Co., Ltd. and Eco Volt Co., Ltd.: October 2, 2026 (subject to change).

Restrictions on appraisal rights: as above - rights lapse for shares resold and reacquired within the period, cannot be withdrawn without Company consent once exercised, and are unavailable to a shareholder who later votes for the merger after notifying dissent.

Effect on the contract: if the aggregate purchase amount for appraisal rights exercised against Rftech Co., Ltd. and Eco Volt Co., Ltd. combined exceeds KRW 15,000,000,000 (fifteen billion won), the merger agreement may be terminated by either company.

14. Board resolution date (decision date): April 13, 2026 - Independent (outside) director attendance: present (1); absent (-) - Audit committee member who is not an independent (outside) director: present * "Independent director" applies to listed companies and "outside director" to unlisted companies.

15. Put option or similar contract: No 16. Securities registration statement required: Yes

17. Future plans for corporate restructuring After the merger, the Company plans to scale down automotive-parts manufacturing, relocate Rftech's Yongin plant equipment and personnel to Eco Volt's Asan site, and raise additional cash through sale of the Yongin plant and Eco Volt's subsidiary SF INNOTEK VINA CO.,LTD. To focus on core competencies, on April 15, 2026 the merged company sold 910,747 of its 1,890,625 RF Bio shares to Access Bio, transferring control and exiting the bio business; the semiconductor-equipment business is also being sold or scaled down. After the merger, Rftech will invest in AI-oriented module and 5G Advanced/6G technology development, with related R&D organizational changes expected.

Rftech currently develops 5G base-station antennas (AU), integrated antenna-filter units (AFU), micro filters, and macro/RU filters as its core products, with design, verification and mass-production capability built on its Samsung Electronics 5G antenna/filter supply experience, including co-design of antennas and filters inside massive MIMO equipment; in the filter field, it has expanded centered on micro filters and RU filters since entering the 5G filter market in 2024. Key technologies Rftech must still develop for 5G Advanced/6G: (1) multi-band antenna/filter technology (n25/n66, n3/n1/n7, etc.); (2) higher-order massive MIMO antenna technology beyond 32T32R/64T64R; (3) high-frequency, low-loss RF design for new bands (n104, FR3, preliminary 6G); (4) sheet-metal resonator, air-strip and monolithic filter structures to cut thickness, weight, loss and cost; and (5) AFU/integrated RF module design optimizing antenna, filter, mechanics, heat dissipation and RF interface together. The Company also plans to advance manufacturing automation (SMT, assembly, PIM measurement, filter tuning, visual inspection).

Technology development schedule for the 5G/5G Advanced/6G RF module business: - 2026: build the 5G product lineup and enter mass production (expand AU/AFU mass production to Samsung Electronics, enter RU filter mass production, stabilize micro filter/macro-RU filter development, build antenna/filter development base for global customers such as Ericsson) - 2027: convert the full 5G product lineup to mass production and prepare 5G Advanced technology (multi-band antennas/filters, FDD-band support such as n25/n66, n3/n1/n7, cost-reduced filter structures) - 2028: advance 5G Advanced response technology (higher-order massive MIMO antennas, high-isolation/low-loss elements, sheet-metal resonator/air-strip/monolithic filter structures, lightweight/thin/simplified-process technology) - 2029: prepare preliminary 6G technology and expand joint development with customers (n104/FR3 band development, high-frequency low-loss materials, integrated AFU design, next-generation RF structure review with Tier-1 customers) - 2030: secure initial 6G RF module technology (6G candidate frequencies, highly integrated RF structures, 128T/256T-class higher-order massive MIMO review, ultra-high-frequency integrated modules, foundation for initial 6G commercialization)

Rftech's new-business spending plan (unit: KRW 100 million, %): 2026 - estimated 5G sales 119, R&D 27, facility investment 131, total 158, ratio to sales 114.21; 2027 - estimated sales 228, R&D 29, facility investment 58, total 87, ratio 33.81; 2028 - estimated sales 503, R&D 29, facility investment 70, total 99, ratio 17.31; 2029 - estimated sales 1,008, R&D 35, facility investment 78, total 113, ratio 9.92; 2030 - estimated sales 1,517, R&D 35, facility investment 68, total 103, ratio 6.07. (Source: Rftech.)

As of the registration-statement filing date, Rftech's development organization totals 33 (antenna 13, filter 17, defense/DPT 3). By end-2026 it plans to add 3 antenna and 2 DPT staff; from 2027, maintain antenna 17/filter 17/DPT 6; by 2028, keep the RF organization near 40; from 2029, expand to around 50. Expected headcount by year (antenna / filter / DPT / RF total): current 13/17/3/33 -> 2026: 16/17/5/38 -> 2027: 17/17/6/40 -> 2028: 17/17/6/40 -> 2029: 22/20/8/50 -> 2030: 22/20/8/50. (Source: Rftech.)

18. Other matters of reference for investment decisions (a) Approval of the merger at the shareholders' meeting is a special resolution matter under Articles 522 and 434 of the Commercial Act; failure to obtain at least two-thirds of attending voting rights and at least one-third of total issued shares could cause the merger to fail. (b) No cash consideration will be paid to shareholders other than payment for fractional shares. (c) The number of new merger shares in "7" above may change depending on exercise of appraisal rights by Eco Volt shareholders after the extraordinary shareholders' meeting approves the merger agreement; no new shares will be issued for treasury shares Eco Volt acquires through such exercises. (d) Eco Volt's financial details in "8" above are based on its 2025 year-end consolidated financial statements. (e) The schedule in "10" above is subject to change pending regulatory approvals and consultations. (f) The closing report meeting in "10" above will be replaced by a board resolution and public notice on October 6, 2026, pursuant to Article 526, Paragraph 3 of the Commercial Act. (g) The proposed share purchase prices are: Rftech Co., Ltd. (surviving company) KRW 9,325; Eco Volt Co., Ltd. (dissolved company) KRW 1,968, each reflecting the respective par-value consolidation/split and capital reduction described above. If no agreement is reached on price, the amount will be calculated under Article 165-5 of the Financial Investment Services and Capital Markets Act and Article 176-7 of its Enforcement Decree based on pre-resolution market trading prices, and a dissenting shareholder may apply to the court to determine the price.

1) Method for calculating Rftech's expected purchase price (base date April 12, 2026): 2-month volume-weighted average price KRW 1,885 (February 13 - April 12, 2026); 1-month KRW 1,819 (March 13 - April 12, 2026); 1-week KRW 1,892 (April 6 - April 12, 2026); base purchase price (average of the three) KRW 1,865; final purchase price after reflecting the 5-for-1 share consolidation: KRW 9,325.

2) Daily closing price, volume and value used in the calculation (unit: KRW, shares): 2026/04/10: close 2,010, volume 4,198,020, value 8,438,020,200 2026/04/09: close 1,549, volume 652,430, value 1,010,614,070 2026/04/08: close 1,542, volume 192,790, value 297,282,180 2026/04/07: close 1,542, volume 303,348, value 467,762,616 2026/04/06: close 1,600, volume 334,470, value 535,152,000 2026/04/03: close 1,554, volume 317,653, value 493,632,762 2026/04/02: close 1,521, volume 431,816, value 656,792,136 2026/04/01: close 1,620, volume 201,997, value 327,235,140 2026/03/31: close 1,639, volume 142,551, value 233,641,089 2026/03/30: close 1,639, volume 238,102, value 390,249,178 2026/03/27: close 1,685, volume 292,984, value 493,678,040 2026/03/26: close 1,783, volume 312,663, value 557,478,129 2026/03/25: close 1,894, volume 562,008, value 1,064,443,152 2026/03/24: close 1,775, volume 193,805, value 344,003,875 2026/03/23: close 1,697, volume 106,309, value 180,406,373 2026/03/20: close 1,759, volume 145,238, value 255,473,642 2026/03/19: close 1,699, volume 140,450, value 238,624,550 2026/03/18: close 1,775, volume 149,647, value 265,623,425 2026/03/17: close 1,780, volume 228,944, value 407,520,320 2026/03/16: close 1,740, volume 124,602, value 216,807,480 2026/03/13: close 1,723, volume 141,769, value 244,267,987 2026/03/12: close 1,712, volume 294,383, value 503,983,696 2026/03/11: close 1,730, volume 613,636, value 1,061,590,280 2026/03/10: close 1,723, volume 172,220, value 296,735,060 2026/03/09: close 1,667, volume 256,764, value 428,025,588 2026/03/06: close 1,805, volume 257,456, value 464,708,080 2026/03/05: close 1,818, volume 591,786, value 1,075,866,948 2026/03/04: close 1,658, volume 941,412, value 1,560,861,096 2026/03/03: close 1,960, volume 7,962,864, value 15,607,213,440 2026/02/27: close 2,365, volume 970,914, value 2,296,211,610 2026/02/26: close 1,821, volume 347,652, value 633,074,292 2026/02/25: close 1,863, volume 213,180, value 397,154,340 2026/02/24: close 1,932, volume 241,419, value 466,421,508 2026/02/23: close 2,020, volume 919,976, value 1,858,351,520 2026/02/20: close 1,771, volume 83,614, value 148,080,394 2026/02/19: close 1,825, volume 162,022, value 295,690,150 2026/02/13: close 1,779, volume 150,329, value 267,435,291 2-month weighted average: KRW 1,885; 1-month: KRW 1,819; 1-week: KRW 1,892; base purchase price: KRW 1,865. (Source: Korea Exchange, krx.co.kr.) For Eco Volt Co., Ltd.'s own appraisal purchase-price basis, see Eco Volt Co., Ltd.'s material event report.

(h) If the shareholders' meeting rejects the merger, appraisal rights lapse and the merger agreement does not take effect. (i) A requesting shareholder cannot withdraw an appraisal-rights request after the exercise period ends. (j) At its board meeting of March 10, 2026, the Company resolved a share consolidation (5 common shares of KRW 500 par value into 1 common share of KRW 2,500 par value), changing total issued shares from 45,241,115 to 9,048,223. (k) Termination conditions in the merger agreement: Article 12 (Conditions Precedent) requires (i) all required board/shareholder approvals and satisfaction of legal requirements, (ii) performance of all material covenants, and (iii) no material adverse change in either party's property, performance or prospects between execution and the merger date (each waivable in writing). Article 13 (Effectiveness and Termination) allows termination before the merger date by (i) mutual written agreement, (ii) failure of either party to obtain shareholders' meeting approval, (iii) material adverse change from force majeure or other cause, (iv) failure of the Article 12 conditions precedent, or (v) the aggregate appraisal-rights purchase amount for both companies exceeding KRW 15,000,000,000 as of expiration of the exercise period; termination requires return/destruction of exchanged data within 14 days, does not affect claims for breach, and Articles 13.2 and 15-17 survive termination.

* For further details, see Rftech Co., Ltd.'s securities registration statement to be filed at a later date. * Related disclosures: see DART filing history for this report.