The F-9 jet valve spring fits most KWA GBB pistols. On their respective diagrams, it appears as M9 part 87, M93R II NS2 part 109, ATP part 71, M11A1 NS2 part 126, M1911 MK Series and M1911A1(serialized version) part 71, kz.75 part 77, TT-33 part 76, MKV part 70.
