Detail Specifications HR-600A I.D. 8mm X O.D. 12mm X7.5M, With 1/4" Air Inlet & Outlet With Plastic Housing,Working pressure 200psi. HR-600B I.D. 6.5mm X O.D. 10mm X7.5M, With 1/4" Air Inlet & Outlet With Plastic Housing,Working pressure 200psi.