Fujica X-mount
The Fujica X-mount was a lens mount created by Fujifilm in the late 1970s and early 1980s for the new Fujica SLR lineup: AX-1, AX-3, AX-5, AX Multi, STX-1, STX-1N, STX-2, MPF105X, MPF105XN. It replaced the M42 screw mount used on their earlier SLRs. The mount is a bayonet type, with a 65° clockwise lock, and a flange focal distance of 43.5 mm.