This listing is for one brand new solid brass in-line compressed air regulator. This regulator has 1/4" female NPT threads on one side and 1/4" male NPT on the other side. It can be installed in either direction. This regulator is most commonly used at the end of a air hose before the air tool for easy and precise adjustment with the turn knob. Specifications: Total length: 1-5/8" Air line hook-ups: 1/4" NPT which measures about 1/2" in diameter. Round turn knob to adjust air flow. All brass construction