Features Premium Material: The air compressor check valve is made of high quality zinc alloy material, which features high strength and durability. Working Principle: One thread connector is for tube connecting and the other thread connectors are for air pressure tank and compressor piston pump. Great Replacement: This valve is used as great replacement for the old or broken check valve of your air compressor. Easy to Install: The air compressor check valve is easy to install with the thread connecting ends. Total Size: 42 x 39mm, Male Thread Size: 1/2" 3/8", Hex Head Size: 18mm. Specifications: Product Name: Air compressor Check Valve Material: Zinc Alloy Color: Golden Thread Diameter: 9.5-10mm 16-16.5mm  20-20.5mm Total Size: 42 x 39mm Male Thread Size: 1/2" 3/8" Hex Head Size: 18mm Note: Please allow a little size error due to manual measurement. Package Included: 1 x Air Compressor Check Valve Package List