Get hydrated! The HyFLO is a streamlined, one-piece bite valve that offers fast-flowing, self-sealing, leak-free performance. Made with a soft, taste-free, medical-grade silicone, the HyFLO stands up to years of use. The bite valve is included on all Big Zip EVO and Hoser Reservoirs and is compatible with all legacy Platypus shutoff valves. The Platypus HyFlo bite valve has a fast flow rate, is drip free and easy to hold in your mouth. Weight is 0.2 oz.