These Alumina Large Gas Lens fit all 17 & 26 series air cooled torches and 18 series water cooled torches,including the Lincoln PTA-17, PTA-18 and PTA-26 torches, Miller Diamondback DB17, DB18 and DB 26 torches,along with the Weld craft WP-17, WP-18 and WP-26 torches.