EASY INSTALLATION: Air compressor check valves are quick and easy to install, no tools required and the threaded ends are easy to install. All corners and raised points of this product are carefully sanded and rounded to avoid hurting your hands. SAFE REPLACEMENT: Before replacing the check valve, make sure the compressor is completely stopped and the pressure is completely relieved. Reminder: Our air compressor check valves are sized for hoses with thread diameters of 9.5-10mm, 16-16.5mm and 20-20.5mm. Please check compatibility and size before purchasing. These three threads are used to connect the compressor, pressure tank and piston pump hoses. Good Performance: Our air compressor check valve is made of high-strength zinc alloy, which has pressure resistance, high performance and high reliability. It does not require much maintenance. The surface is also finely polished to ensure smooth edges and surfaces. Application: This air compressor check valve is a great replacement for an old valve.