Film back can be used only with Bronica ETRS medium format camera.
The ETRS is an improved version of the ETR. The main improvement is the interchangeable viewfinder system. The newer AE II and III finders are not fully compatible with the older ETR cameras, because there is a new electronic connector pin. The shutter button lock has been redesigned. It has three settings, unlocked, shutter release button lock but drive and cable release unlocked, and all locked.
Introduced as a commemorative of the 60th year of Contax cameras, the S2 uses the Contax/Yashica bayonet mount in order to accept Carl Zeiss T lenses. It is a simple camera with a mechanical shutter that provides shutter speeds up to 1/4000 second and a 1/250 second X sync.