Air compressor check valve, 1/2" Compression x 1/2" MPT with 1/8" hole; plug hole if not needed.  https://mastertoolrepair.com/1-8-blk-steel-plug-s-h-100b6e/ If the small unloader (bleeder) valve on or under your pressure switch leaks constantly...

Keep your air compressor from sliding all around your vehicle or floor. Order extra for future use.Specifications Height: 3/4"  Diameter: 1-1/2"

Unloader Valve - Yes  90 degree  On/Off Switch - YES, OEM Model

1/4" NPT wingnut drain cock. Prevent rust from ruining your air compressor tank by draining your tank daily. Keep an extra around for a spare.Extra DetailsThis was a new check valve installed less than a year ago. Due to the tanks not being drained, this...