Pressure Switch
Rol-Air Electric Compressor Parts

Price: $69.41
Found under the following brands:
Grip Rite, Master Force, Rol-Air, Norgren, Snap-On
145/175 PSI. Includes unloader valve, switch and cover. If your pressure switch is leaking out of the small bleeder valve on the side or if located underneath, order a tank check valve instead, your pressure switch is ok.