Unfortunately at this time theseals areno longeravailable for this type of end cap, however new end caps are available. The older tools had a pressure relief system that would blow in the event of excessive pressure being applied to the tool. The seals in the pressure relief valve would deteriorate over time causing the unit to leak at all pressures. The current design no longer has a pressure relief valve in it, and will no longer fail in the same manner. OSHA does not require this pressure relief system. Click here to visit our Bostitch ServiceNet website to purchase a new end cap.