Quite often this little rubber boot that covers the actuating pin gets damaged, lost, or swollen if the seals leak.

This replacement contains the rubber boot, actuating pin and spring to fit all late model AJP Clutch and Brake Master Cylinders. 

Does not fit late 80's to mid 90's AJP Master cyliders with the BIG dust boot. (See this LINK)

Works at a pinch on Gremica Master cylinders found on Beta's. This dust boot is a hair smaller OD, so it fits but just not as tightly as on an AJP M/C. Gremica dont sell just the dust boot, you have to purchase a complete seal kit, so if you just need this external boot it will do the job.

Does NOT fit the new Braktec Master cylinders that have a larger concertina boot.