These collets are for use with a 3/32” Tungsten. The collets have a part number13N23. They fitall 9 series air cooled torches and 20 series water cooled torches, including the Lincoln PTA-9, PTA-9V and PTA-20 torches, Miller Diamondback DB9 and DB 20 torches, along with the Weldcraft WP-9, WP-9V and WP-20 torches.