X0609 4 2026-10-19 1 0001666138 Atkore Inc. ATKR 0002034019 Alvey James William false 16100 S. LATHROP AVENUE HARVEY IL 60426-6021 0 1 0 0 Chief Accounting Officer 0 Common Stock 2026-10-19 4 A 0 999.8442 0 A 6449.2814 D Common Stock 2026-10-19 4 D 0 6449.2814 95 D 0 D On October 19, 2026 (the "Closing Date"), pursuant to the Agreement and Plan of Merger, dated August 2, 2026 (the "Merger Agreement"), by and among Atkore Inc. ("Atkore" or the "Company"), Prysmian S.p.A., a company organized under the laws of the Republic of Italy ("Buyer"), Trinity Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Buyer ("Merger Sub"), and, solely as provided in certain sections of the Merger Agreement, Prysmian Cables and Systems USA, LLC, a Delaware limited liability company, Merger Sub merged with and into the Company (the "Merger"), with the Company surviving the Merger as a wholly owned subsidiary of Buyer (the "Surviving Corporation"). Represents the number of shares of Common Stock underlying unvested performance restricted stock units (a "PSU"), that became earned in connection with the Merger (including any amounts accrued for dividend equivalent units), determined in accordance with the terms of each such PSU. At the effective time of the Merger (the "Effective Time"), each share of common stock of Atkore, par value $0.01 per share ("Common Stock") issued and outstanding immediately prior to the Effective Time, was (except as otherwise provided in the Merger Agreement) converted into the right to receive $95.00 in cash, without interest (the "Merger Consideration"). Includes restricted stock units ("RSUs") and any amounts accrued for dividend equivalent units thereon. Under the Merger Agreement, at the Effective Time, each outstanding RSU, whether vested or unvested, was deemed fully vested and canceled and converted into the right to receive a cash payment from the Surviving Corporation equal to the product of (A) the Merger Consideration and (B) the total number of shares of Common Stock underlying such RSU. Includes PSUs and any amounts accrued for dividend equivalent units thereon. Under the Merger Agreement, at the Effective Time, each outstanding PSU that became earned in connection with the Merger was canceled and converted into the right to receive a cash payment from the Surviving Corporation equal to the product of (A) the Merger Consideration and (B) the total number of shares of Common Stock underlying such PSU, as determined in accordance with the terms of each such PSU. The foregoing descriptions in the explanatory footnotes are qualified in their entirety by reference to the terms of the Merger Agreement. In the event of any conflict between the descriptions above and the terms set forth in the Merger Agreement, the terms set forth in the Merger Agreement shall control. /s/ Daniel S. Kelly, Attorney-in-Fact for James W. Alvey 2026-10-21