Check the listing for details. Replacement Shutter Brake Bumper for Minox A/B. Condition: New. Listed at 5.00 USD. The black part shown circled in red is what is called the shutter brake bumper. All mechanical Minox 8X11 cameras have one and it is basically a small black rubber washer which acts as a stop for the shutter mechanism. On early A cameras (under about serial number 50,000) this part will often be dried, cracking or completely deteriorated. Often you will see chunks of black material floating around the viewfinder of cameras which have a degraded bumper. I believe that after serial number 50,000 (approximately) that Minox changed the material and most cameras after that will not exhibit any degradation of this part. The shutter mechanism will not operate properly without this small, simple part so it is critical that it be replaced if it is bad. So, if you are working on a camera in the early range or notice that the bumper in your camera is dried, hard or missing and need a new bumper, I do have them available for sale for $5 each.