Hookit disc pad enables easy sanding disc change-out, maximizing disc life. Dust extraction HookitT back up pad (clean sanding) is constructed on foam material. Back up pad itself has a 5/16-24 internal thread, and the kit includes 5 adapters that convert it to 1/4-20 external threads, 1/4-20 iInternal threads, 1/4-28 external threads, 5/16-24 external threads, or 6mm-1.0 external threads.