Compatible with Cyclone Bladders by Outdoor Products only Threaded screw-on attachment Molded TPE soft bite Replaces worn and damaged bite valves 2-Pack The item you are looking at is a new 2 pack bite valve replacement kit for Cyclone hydration bladders made by Outdoor Products. The bite valves have a threaded screw attachment and Molded TPE (Thermo Plastic Elastomer) soft bite. There are 2 replacemnt valves in this box.