Our check valves is brass and stainless steels, which can unnecessary backflow This valves set is, resistant to highly temperatures and highly pressure and has good rust protections : our filter check valves is connect to pipes and hoses by external thread, just a few turn to tighten our check valves Wide applications: Our check valves water is suitable for water suction pipes, pumps, fountains, washing machines and garden sprinklers and ensures comfort At end of the 1 / 2 inch check valves there is a fine mesh stainless steel filter that prevents dirt and particles from entering the water supply and prevents the liquid in the pipe from flowings back into the water supply, Manufacturer: XIBEIDIANZI