1/8" PT male thread inlet connection; Overall valve dimension (L*W): 39 x 17mm (1.54" x 0.67") This air compressor/tank pressure relief valve is a protection to protect the compressor from back pressure It is mainly installed in small air compressor systems, gas storage tank, air receiving tank and other related applications Screw the pressure relief valve into the manifold and use a wrench to fix (Add additional sealant if necessary) (Always depressurize the tank before servicing an air compressor) Metal construction and stainless steel spring for corrosion resistance and long-lasting performance The valve is an indispensable equipment of the air compressor. This pressure relief valve is a protection to protect the compressor from back pressure. Specification: Product Name: Pressure Relief Valve Material: Metal Color: Golden, Red Thread Diameter: 9.5mm / 0.37 inch (1/8 inch PT) Overall Dimension: 39 x 17mm / 1.54 x 0.67 inch (H*D) Package Content: 1 x Pressure relief valve Delivery quantity: 1 piece Product color: gold Product size: 39 x 17 mm Note: Manual measurement, please allow 1 - 3cm error!!!Yeuri