; and (ii) 75 percent domestic content, the Secretary shall add 15 additional percent to the component’s domestic content when calculating the domestic content of the rolling stock; and (B) in no case may a component exceed 100 domestic content when calculating the domestic content of the rolling stock. (3) Rolling stock frames or car shells In calculating the cost of the domestic content of the rolling stock under subsection (b)(3), in the case of a rolling stock procurement receiving assistance under this chapter in which the average cost of a rolling stock vehicle in the procurement is more than $300,000, if rolling stock frames or car shells are not produced in the United States, the Secretary shall include in the calculation of the domestic content of the rolling stock the cost of the steel or iron that is produced in the United States and used in the rolling stock frames or car shells. (4) Treatment of waived components and subcomponents In this section, a component or subcomponent waived under subsection (b) shall be excluded from any part of the calculation required under subsection (b)(3)(A). (5) Zero-emission vehicle domestic battery cell incentive The Secretary shall provide an additional 2.5 percent of domestic content to the total rolling stock domestic content percentage calculated under this section for any zero-emission vehicle that uses only battery cells for propulsion that are manufactured domestically. (e) Certification of domestic supply and disclosure (1) Certification of domestic supply If the Secretary denies an application for a waiver under subsection (b), the Secretary shall provide to the applicant a written certification that— (A) the steel, iron, or manufactured goods, as applicable, (referred to in this paragraph as the item ) is produced in the United States in a sufficient and reasonably available amount; (B) the item produced in the United States is of a satisfactory quality