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...

Old Part Numbers: CW000800AV, 69DJAAir compressor bleeder (unloader) valve. Replace if broken, but replace the check valve if this constantly leaks after the compressor shuts off.

CTB1412 hose barb fitting for air compressor in-tank check valve. A hose barb is defined as one or more continuous ridges or bumps on a fitting that are used to grip the inside diameter of a tube and seal the connection.