OEM replacement check valve for Rolair air compressors. This is used with Rolair Bull air compressor models. This check valve features a 3/8" Male Flare thread and a 3/8" Male NPT with an unloader valve that accepts a 1/4" tubing. Specifications: • 3/8" Male Flare Line Input • 3/8" Male NPT Tank Input • Inverted Compression Unloader Port: Accepts 1/4" Tubing • Part Number: FC347043000.