[Amended] Material event report (rights offering)

What happened

Material Event Report (Rights Offering Decision) Seongwon Energytech Co., Ltd. Amendment Report August 4, 2026

1. Disclosure document subject to amendment: Material Event Report (Rights Offering Decision) 2. Date of initial submission of the disclosure document subject to amendment: February 27, 2026 3. Amendment details

Item: Rights Offering Decision Reason for amendment: The Company filed for commencement of rehabilitation proceedings on April 14, 2026, and received an order for preservation of property and a comprehensive injunction on April 16, 2026, and a decision commencing rehabilitation proceedings on May 8, 2026. Pursuant to Article 55, Paragraph 1 of the Debtor Rehabilitation and Bankruptcy Act, from the commencement of rehabilitation proceedings until their conclusion, the Company may not issue new shares or bonds or increase its capital or contributions, and has accordingly decided to withdraw this rights offering. Before amendment: [the entire rights offering decision item] After amendment: Deleted in its entirety

Material Event Report / Matter Subject to Mandatory Exchange Disclosure To: Financial Services Commission / Korea Exchange August 4, 2026

Company name: Seongwon Energytech Co., Ltd. Representative Director: Oh Yoon-ho Head office address: 203-160 Jimun-ro, Wongok-myeon, Anseong-si, Gyeonggi-do Phone: 031-611-7227 Website: http://www.youilet.com Preparer: (Title) Legal Custodian and Representative Director (Name) Oh Yoon-ho (Phone) 031-611-7227

Rights Offering Decision

1. Type and number of new shares: Common shares (shares) -; Other shares (shares) -

2. Par value per share (KRW): -

3. Total shares issued before the offering: Common shares (shares) -; Other shares (shares) -

4. Purpose of capital raising: Facility funds (KRW) -; Business acquisition funds (KRW) -; Working capital (KRW) -; Debt repayment funds (KRW) -; Funds to acquire securities of other companies (KRW) -; Other funds (KRW) -

5. Method of capital increase: Third-party allotment

※ Matters concerning other shares: Basis in the articles of incorporation -; Details of the shares -; Other -

6. New share issue price: Common shares (KRW) -; Other shares (KRW) -

7. Base share price: Common shares (KRW) -; Other shares (KRW) -

7-1. Method of calculating the base share price: the lower of [the simple average of the weighted arithmetic average closing prices for the past 1 month, past 1 week, and most recent day, each calculated from the day before the board resolution date, and the weighted arithmetic average closing price for the most recent day]

7-2. Discount or premium rate on the base share price (%): -

7-3. Basis for the discount (premium) rate: -

8. Basis in the articles of incorporation for the third-party allotment: -

9. Payment date: -

10. Dividend record date for new shares: -

11. Expected date of delivery of new share certificates: -

12. Expected listing date of new shares: -

13. Whether a backdoor listing occurred due to an in-kind contribution: No - Whether there was an in-kind contribution: No - Whether the in-kind contribution property includes shares of an unlisted company: Not applicable - In-kind contribution value of shares to be paid in: In-kind contribution value (KRW) -; percentage of the Company's total assets in the most recent fiscal year (%) -; number of shares to be paid in -

14. Whether backdoor listing requirements are met: Not applicable

15. Date of board resolution (decision date): - - Independent (outside) director* attendance: Present (persons) -; Absent (persons) - - Attendance of auditor (audit committee): -

16. Whether subject to filing of a securities registration statement: No

17. Reason for exemption from filing: -

18. Whether subject to a prohibited short-selling period for subscription: No; Start date -; End date -

19. Whether subject to Fair Trade Commission reporting: Not applicable * Applies to independent directors for listed companies and outside directors for unlisted companies

20. Other material matters relevant to investment decisions - Not applicable. ▶ When using as the base share price the lower of [the simple average of the weighted arithmetic average closing prices for the past 1 month, past 1 week, and most recent day, and the weighted arithmetic average closing price for the most recent day], the following table is added (Unit: shares, KRW): Weighted arithmetic average price for the past 1 month (A): trading volume -, trading value -, price - Weighted arithmetic average price for the past 1 week (B): trading volume -, trading value -, price - Weighted arithmetic average price for the most recent day (C): trading volume -, trading value -, price - Simple arithmetic average of (A), (B), (C) (D): - Base share price (the lower of (C) and (D)): - Discount or premium rate (%): - Issue price: -

【Basis, Purpose, etc. of the Third-Party Allotment】 Basis in the articles of incorporation: -; Purpose of the third-party rights offering: -

【Specific Purpose of Use of Funds Raised Through the Third-Party Allotment】 【For working capital/other funds】 (Unit: KRW) Use of funds: Working capital; Details*: -; Amount planned to be used by year: 2026 -, 2027 -, 2028 onward -, Total -

【Selection Process, Transaction History, Allotment Details, etc. by Third-Party Allottee】 Third-party allottee: -; Relationship with the Company or largest shareholder: -; Selection process: -; Transaction history and plans within 6 months before and after the capital-increase decision: -; Number of shares allotted (shares): -; Note: -