Retainer Buffer JSG-9121NS for JAT-800A, JAT-821A (730221)

Retainer buffer for the JET JAT-800A and JAT-821A air hammers (JSG-9121NS). The buffer absorbs the impact energy that travels back through the retainer at the end of each stroke — its job is to keep that recoil from beating up the threads on the hammer body. OEM replacement; buffer is a designed-to-wear part, replace with every rebuild kit.