... valve 2.Material:Silicone,NBR,FKM,FVMQ 3.Tube OD:8.5MM,Heigth:16.6mm Silicone Duckbill Valve ItemDuckbill ValveBrandRAMISCountry of ... BlackPerformanceWear resistant and corrosion resistant,immediate positive seal,position independen,variable opening pressure trough seat thickness.FunctionAct as backflow prevention devices ... according to ASTM, DIN, SAE,VDA6.1, UL, FDA, JIS . 8.5mm duckbill valve