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...

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

Old Part Numbers: AB-ACG18

Old Part Numbers: K-0286