[Amended] Material event report (merger)

What happened

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

1. Disclosure document being amended: Material event report (decision to merge companies) 2. Original filing date: April 14, 2026 3. Amendment: Item 5 (Basis for calculating the merger ratio); reason: correction of error - Before: Eco Volt Co., Ltd. reference share price KRW 766; After: KRW 773

Material event report / Matters subject to KRX reporting obligations. To: Financial Services Commission / Korea Exchange. July 28, 2026. Company name: Eco Volt Co., Ltd. Representative Director: Han Jae-gwan Head office: 433-31 Sandong-ro, Eumbong-myeon, Asan-si, Chungcheongnam-do Phone: 041-539-2500 Website: http://ecovoltdynamics.co.kr Preparer: (Title) Executive Director (Name) Jeong Gi-do (Phone) 041-539-2500

Decision to Merge Companies (This is Eco Volt's own filing on the same merger covered by Rftech Co., Ltd.'s material event report, RCEPT 20260728000340; the merger structure, ratio, pricing method and legal basis are identical and are not fully repeated here. Eco-Volt-specific figures, and sections unique to this filing, are given in full below. Long condensed per the length rule; all source figures are retained.)

1. Merger method: Rftech Co., Ltd. absorbs Eco Volt Co., Ltd. (dissolved); surviving company name after merger: Rftech Co., Ltd. 2. Purpose: the Company seeks to exit its low-margin, low-growth automotive-lighting business by merging with a company with growth potential, maximizing shareholder value; Rftech, the surviving company, sought to strengthen its 5G capability and expand into telecommunications. 3. Material effects: same shareholding structure as in Rftech's filing - Osung Advanced Materials Co., Ltd. holds 30.46% of Rftech and 29.89% of Eco Volt before the merger (combined with related parties 39.95% and 29.94% respectively); after the merger Osung's stake in the surviving company is expected to be 30.29% (combined with related parties 36.82%), with no change of largest shareholder. Rftech's Yongin plant equipment/staff will move to Eco Volt's Asan site; Rftech's Yongin plant and Eco Volt's Vietnamese subsidiary SF INNOTEK VINA CO.,LTD are both being sold for additional cash. On April 15, 2026 the merged company also sold 910,747 of its 1,890,625 RF Bio shares to Access Bio, exiting the bio business.

4.-5. Merger ratio and calculation basis: identical method and result as Rftech's filing - 1 : 0.2027268, under Article 176-5, Paragraph 1, Item 1 of the Enforcement Decree of the Financial Investment Services and Capital Markets Act. Rftech's par value was consolidated from KRW 500 to KRW 2,500 per share, and Eco Volt's was split from KRW 1,000 to KRW 500 and then reduced 80% without compensation, before the reference prices below were applied. Base date April 12, 2026: Rftech 1-month weighted average KRW 1,819, 1-week KRW 1,892, latest close (April 10, 2026) KRW 2,010, reference price KRW 1,907, after consolidation KRW 9,535, merger value KRW 9,535; Eco Volt 1-month weighted average KRW 788, 1-week KRW 766, latest close KRW 766, reference price KRW 773, after stock split KRW 386.5, after capital reduction without compensation KRW 1,932.5, merger value KRW 1,933.

6. External valuation: not applicable (same reasoning as Rftech's filing). 7. New merger shares: common shares 4,111,636; class shares: none.

8. Merger counterparty: Rftech Co., Ltd. - main business: broadcasting and wireless communication equipment manufacturing; relationship: affiliated company. Financial details for the most recent fiscal year (KRW): total assets 407,430,424,081; capital stock 16,044,629,500; total liabilities 221,393,790,005; sales 266,007,649,510; total equity 186,036,634,076; net income -30,470,680,477. External auditor: Samil PricewaterhouseCoopers, opinion: unqualified.

9. Newly incorporated merger company: not applicable.

10. Merger schedule: merger agreement date April 13, 2026; shareholder record date June 30, 2026; dissent-notice period August 6 - August 28, 2026; shareholders' meeting expected August 31, 2026; appraisal rights exercise period August 31 - September 21, 2026; trading-suspension period October 1 - October 28, 2026; creditor objection period September 1 - October 2, 2026; merger effective date October 3, 2026; merger registration date October 16, 2026; new-share listing date October 29, 2026. (This filing additionally sets a trading-suspension period, left blank in Rftech's filing, and sets the closing-report-meeting substitute board notice for September 2, 2026, versus October 6, 2026 in Rftech's filing.)

11.-12. Backdoor listing: not applicable to either.

13. Appraisal rights: same legal basis as Rftech's filing. Expected purchase price for Eco Volt shares: KRW 1,968, calculated (base date April 12, 2026) from a 2-month volume-weighted average of KRW 806 (February 13 - April 12, 2026), 1-month KRW 788 (March 13 - April 12, 2026), 1-week KRW 766 (April 6 - April 12, 2026), base price KRW 787, halved for the stock split to KRW 393.5, then multiplied five-fold for the capital reduction without compensation to a final KRW 1,968.

Daily closing price, volume and value used in the calculation (KRW, shares): 2026/04/10: close 766, volume 62,172, value 47,623,752 2026/04/09: close 766, volume 53,162, value 40,722,092 2026/04/08: close 765, volume 345,624, value 264,402,360 2026/04/07: close 764, volume 87,597, value 66,924,108 2026/04/06: close 787, volume 33,953, value 26,721,011 2026/04/03: close 788, volume 75,987, value 59,877,756 2026/04/02: close 791, volume 48,966, value 38,732,106 2026/04/01: close 800, volume 49,500, value 39,600,000 2026/03/31: close 798, volume 54,435, value 43,439,130 2026/03/30: close 802, volume 61,864, value 49,614,928 2026/03/27: close 802, volume 178,749, value 143,356,698 2026/03/26: close 783, volume 51,873, value 40,616,559 2026/03/25: close 782, volume 28,538, value 22,316,716 2026/03/24: close 784, volume 41,995, value 32,924,080 2026/03/23: close 777, volume 38,757, value 30,114,189 2026/03/20: close 798, volume 52,546, value 41,931,708 2026/03/19: close 790, volume 59,029, value 46,632,910 2026/03/18: close 795, volume 128,298, value 101,996,910 2026/03/17: close 807, volume 135,458, value 109,314,606 2026/03/16: close 806, volume 239,616, value 193,130,496 2026/03/13: close 797, volume 40,495, value 32,274,515 2026/03/12: close 804, volume 59,863, value 48,129,852 2026/03/11: close 783, volume 67,735, value 53,036,505 2026/03/10: close 773, volume 82,681, value 63,912,413 2026/03/09: close 749, volume 101,507, value 76,028,743 2026/03/06: close 784, volume 73,505, value 57,627,920 2026/03/05: close 785, volume 179,920, value 141,237,200 2026/03/04: close 785, volume 388,900, value 305,286,500 2026/03/03: close 808, volume 246,971, value 199,552,568 2026/02/27: close 824, volume 280,577, value 231,195,448 2026/02/26: close 833, volume 188,703, value 157,189,599 2026/02/25: close 846, volume 294,038, value 248,756,148 2026/02/24: close 844, volume 461,096, value 389,165,024 2026/02/23: close 850, volume 300,470, value 255,399,500 2026/02/20: close 815, volume 222,167, value 181,066,105 2026/02/19: close 831, volume 717,595, value 596,321,445 2026/02/13: close 792, volume 1,293,295, value 1,024,289,640 2-month weighted average close KRW 806; 1-month KRW 788; 1-week KRW 766; base purchase price KRW 787. (Source: Korea Exchange, krx.co.kr.) For Rftech Co., Ltd.'s own appraisal price basis (KRW 9,325), see Rftech Co., Ltd.'s material event report. Rights lapse if the shareholders' meeting rejects the merger and cannot be withdrawn after the exercise period ends. As in Rftech's filing, the merger agreement may be terminated by either party if the combined appraisal-rights purchase amount for both companies exceeds KRW 15,000,000,000. Place of receipt for Rftech Co., Ltd. (surviving company): 60 Jukyangdae-ro 1763beon-gil, Wonsam-myeon, Cheoin-gu, Yongin-si; for Eco Volt Co., Ltd. (dissolved company): 433-31 Sandong-ro, Eumbong-myeon, Asan-si.

The Company's capital history leading into the merger: at its board meeting of February 2, 2026, the Company resolved a paid-in capital reduction effective April 20, 2026, reducing issued shares from 63,415,904 to 50,732,723 (trading suspended April 17 - May 6, 2026); the same board resolved a stock split (one KRW 1,000 common share into two KRW 500 shares), increasing issued shares from 50,732,723 to 101,465,446 (trading suspended May 12 - June 15, 2026); and a capital reduction without compensation effective May 26, 2026 (five KRW 500 shares consolidated into one), reducing issued shares from 101,465,446 to 20,293,089 (trading suspended May 12 - June 15, 2026).

14. Board resolution date: April 13, 2026 (independent/outside director: present 1, absent -; audit committee member who is not independent/outside director: present). 15. Put option: No. 16. Securities registration statement required: Yes.

17. Future corporate restructuring plans: substantially identical to Rftech Co., Ltd.'s own filing (RCEPT 20260728000340) - same 5G/5G Advanced/6G technology roadmap for 2026-2030, same new-business spending table (estimated 5G-business sales of KRW 119/228/503/1,008/1,517 (unit: 100 million won) for 2026-2030 against total new-business spending of KRW 158/87/99/113/103 for the same years), and same R&D headcount plan (33 -> 38 -> 40 -> 40 -> 50 -> 50). (This filing also notes industry forecasts that 5G's share of mobile data traffic will keep rising, reaching roughly 83% by 2031, as part of the rationale for the 5G Advanced/6G investment.) This filing also sets out Rftech's historical product-line sales (KRW million; columns are 2026 Q1 / 2025 / 2024 / 2023 / 2022 / 2021 / 2020 / 2019): TA 11,168 / 41,375 / 91,292 / 95,818 / 117,418 / 135,566 / 140,460 / 120,892; DLC 22,627 / 92,490 / 92,502 / 78,848 / 78,983 / 76,084 / 71,982 / 66,366; ANT·STY 4,918 / 37,004 / 49,781 / 37,707 / 57,541 / 67,608 / 13,369 / 34,041; 5G antenna modules 1,839 / 3,011 / 1,387 / 2,792 / 3,416 / 16,886 / 14,474 / 35,417; other accessories, etc. 7,595 / 30,193 / 42,500 / 74,068 / 90,152 / 18,502 / 10,728 / 22,566; bio (HA filler, etc.) 4,859 / 18,910 / 20,431 / 19,256 / 13,045 / 11,178 / 6,845 / 5,210; equipment (coater/VCD, etc.) 14,476 / 43,024 / 60,429 / 5,889 / - / - / - / -; total 67,482 / 266,007 / 358,323 / 314,378 / 360,554 / 325,824 / 257,858 / 284,492. Rftech's facility/technology-infrastructure investment: 2026 approx. KRW 3,529 million for 5G RF antennas (including an anechoic chamber at KRW 3,000 million) plus KRW 333 million for RF filters; 2027 approx. KRW 500 million; 2028 approx. KRW 500 million; 2029 approx. KRW 1,000 million; 2030 approx. KRW 500 million.

18. Other matters of reference for investment decisions (fairness-review process specific to this filing): Both companies' April 8, 2026 boards initially voted against establishing a special committee or retaining outside experts before the April 13, 2026 merger resolution, citing the urgency of securing roughly KRW 100 billion in liquidity for Rftech's new business and the risk of losing the opportunity. Both boards later resolved, on May 28, 2026, to establish special committees after the fact as a supplementary fairness measure, given the structural conflict-of-interest concerns in a merger between affiliates sharing the same largest shareholder, Osung Advanced Materials Co., Ltd.

Rftech's officers approving the merger: Representative Director Cho Kyung-sook (b. 1960.02; also chair/director of Osung Advanced Materials Co., Ltd. and chairman of Eco Volt Co., Ltd.; recused under Commercial Act Article 398 self-dealing rules), in-house director Kim Du-in (b. 1985.04; also representative director of Osung Advanced Materials Co., Ltd. and Kumho HT Co., Ltd.), and outside director Choi Young-cheol (b. 1976.06; accountant, Samdeok Accounting Corp.).

Rftech's special committee (established post hoc): chair Choi Young-cheol (outside director, b. 1976, Hanyoung Accounting Corp. SaT division partner accountant 2007-2023, Samdeok Accounting Corp. accountant 2023-present); members Lee Ki-ho (accountant/CEO of KJ&Partners, Hanyoung Accounting Corp. finance-advisory partner 1992-2018, founded KJ&Partners 2002-present), Lee Yu-ri (accountant, Samsung Accounting Corp. tax advisory 2011-2014, Sangjiwon Accounting Corp. partner 2015-present), and Kim Bong-jun (attorney, Minju Law, attorney since 2008-present; legal advisor, Korea Housing Finance Corporation guarantee review committee, 2022). It met three times (May 29, June 11 and June 18, 2026) and engaged Yicheon Accounting Corporation (financial, retained June 9-19, 2026; 3 staff, 216 hours, fee KRW 40 million) and Sejong Law (legal, retained June 9-19, 2026; 5 staff, 30 hours, fee KRW 20 million).

Eco Volt's special committee: chair Oh Chang-jin (outside director, b. 1960.06, former Director of Legal Affairs, Financial Supervisory Service); members Kim Ji-eung (professor, Yonsei University AI Convergence College, b. 1983.01, Ph.D. Computer Science Yale University, Google Korea 2020-2022, Inha University faculty 2022-2024, Yonsei faculty 2024-present), Yoon Gi-eop (accountant, Yegwang Accounting Corp., b. 1987.01, B.A. Mechanical Engineering Seoul National University, Samil PwC 2014-2023, Yegwang Accounting Corp. 2023-present), and Jo Jang-gon (attorney, Yeoyul Law, b. 1976.12, Korea University Law, Korean Bar Association Commercial Law subcommittee 2018-2023, Yeoyul Law representative attorney 2021-present). It met three times (May 29, June 15 and June 19, 2026) and engaged Jeongdong Accounting Corporation (financial, retained June 8-19, 2026; 3 staff, 208 hours, fee KRW 25 million) and Baker McKenzie KL Partners (legal, retained June 4-19, 2026; 2 staff, 30 hours, fee KRW 20 million).

Independent intrinsic-value appraisals (asset value weighted 1, profit value weighted 1.5; valuation date December 31, 2025; WACC risk-free rate 3.4%, market risk premium 8.0%, size premium 4.0%): - Yicheon Accounting Corp. (for Rftech): Rftech intrinsic value KRW 4,922-5,692/share (asset value KRW 5,082, profit value KRW 4,815-6,098; WACC 11.4%, cost of debt 9.8%, tax rate 24.2%); Eco Volt intrinsic value KRW 2,223-2,313/share (asset value KRW 2,843, profit value KRW 1,810-1,959; WACC 11.6%, cost of debt 8.5%, tax rate 22%); implied ratio range 1:0.3906541-1:0.4699142, within which the statutory reference-price ratio of 1:0.4053487 falls, confirming its adequacy. - Jeongdong Accounting Corp. (for Eco Volt): Rftech intrinsic value KRW 4,626-5,423/share (asset value KRW 5,082, profit value KRW 4,322-5,650; WACC 11.5%); Eco Volt intrinsic value KRW 2,168-2,263/share (asset value KRW 2,843, profit value KRW 1,718-1,876; WACC 11.6%); implied ratio range 1:0.4002849-1:0.4892949, likewise bracketing 1:0.4053487. A narrative recap elsewhere in the same report restates Eco Volt's figures slightly differently, as KRW 2,171-2,264/share intrinsic value with profit value KRW 1,722-1,877 (as stated in the filing).

Sensitivity of the merger terms to the board-resolution date, as reviewed by Eco Volt's committee: April 13, 2026 - Rftech close KRW 2,010, Eco Volt close KRW 766, merger values KRW 9,535/KRW 1,933, ratio 0.202726796, new shares 4,111,636, Osung's allotment 1,229,612, Osung's post-merger stake 30.29%; April 14, 2026 - Rftech close KRW 2,610, Eco Volt close KRW 764, merger values KRW 12,105/KRW 1,930, ratio 0.159438249, new shares 3,233,673, Osung's allotment 967,051, stake 30.31%; April 15, 2026 - Rftech close KRW 2,545, Eco Volt close KRW 827, merger values KRW 12,280/KRW 2,040, ratio 0.16612378, new shares 3,369,266, Osung's allotment 1,007,601, stake 30.31%.

Legal opinions (Sejong Law for Rftech; Baker McKenzie KL Partners for Eco Volt) found the merger's purpose, pricing and procedure acceptable: Eco Volt's roughly KRW 86 billion in cash-equivalent assets would transfer to Rftech, enabling repayment of roughly KRW 21 billion in borrowings and funding of 5G module R&D; each statutory step (board resolution April 13, 2026; voting-rights restriction on interested director Cho Kyung-sook under Commercial Act Article 391; material event report filed April 14, 2026 and re-filed June 11, 2026; shareholders' meeting set for July 31, 2026; creditor objection period August 1 - September 1, 2026) was confirmed complete or scheduled, with no evidence that the largest shareholder dictated the ratio or the timing of the board resolution. The opinions cited precedent recognizing market-price-based merger ratios set under the statutory formula as not unfair absent evidence of fabricated data or market manipulation, including Supreme Court rulings of 2008.1.10 (case 2007Da64136), 2009.4.23 (cases 2005Da22701 and 2005Da22718), and 2017.9.12 (case 2015Da70044), and Seoul Central District Court rulings of 2015.7.1 (case 2015Kahap80582) and 2017.10.19 (case 2016Gahap510827, the Samsung C&T-Cheil Industries merger dispute).

Both special committees' final opinions, reported to their respective boards on June 23-24, 2026 and approved by both boards, concluded the merger's purpose, terms and procedure were fair to each company and its shareholders as a whole, notwithstanding that the committees were formed only after the original board resolution of April 13, 2026.

* For further details, see Rftech Co., Ltd.'s securities registration statement to be filed at a later date. (condensed translation)