Old Part Numbers: SSF-3158-1This is the screw that holds down the piston cover, on the top of the piston.

Air compressor check valve. 3/8" Comp x 1/2" MPT with 1/8" FPT side port.  The check valve is a one-way valve that prevents air from back-feeding from the air tank. If your unit has a hard time restarting when trying to cycle or your pressure switch...

Order this if ordering valve plate or a new head.

Old Part Numbers: SSW-7367Strain relief for air compressor power cord.

Old Part Numbers: AC-0385, D21299, Z-D21299(4 PORT) 100/125 PSI If your valve is leaking on the side of the switch, do not order this part. Order check valve instead.