The F-12 Cylinder return spring fits most KWA GBB Pistols and SMGs. Sold individually. On respective diagrams, this part appears as M9 part 85, M93R II part 107, M226 part 84, M1911 MK Series and M1911A1 part 72, kz.75 part 76, KMP9 part 87, TT-33 part 73, and MKV part 69.