The Mamiya M is a 35mm film point and shoot from the 80s. The camera is a bit funky it doesn't have a normal power switch, there is an interlock that acts like one. It's the front lens cap, if it is on, the cap depresses a lever which stops the camera from being able to fire.

I have not seen one of these original caps and so I just 3D modelled one. It seems to fit on just fine and indeed does prevent the shutter from going off in transport.