This sale is for one very rare, really excellent condition Mamiya RB67 rear body cap, suitable for use with all RB67 cameras – the RB67 Pro, ProS and ProSD. It will NOT fit RZ67 cameras.
This cap keeps dirt out of your camera when the back has been removed from the camera. It connects to the rotating back adapter in place of a back. It has only normal very minor signs of use. Try finding another one – these are almost impossible to find.