Universal Regulator: 4-port, two 1/4" FPT ports, and two 1/8" FPT ports (gauges sold separately here). The regulator controls the amount of air in your air compressor hose. Replace this if you're not able to adjust the PSI to your hose or if it leaks...

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.

Screw, #10-14 x 2.50". This is the screw for the air intake muffler cover (2 used).

Screw (fastener) for the motor/pump shroud.

Screw for the pump cooling fan.