The best-performing valve in the industry. The Blaster Bite Valve comes with a dust cover to protect you from grittier elements, it’s leak-proof, self-sealing and easy to disassemble for cleaning. It’s a clear winner. High-flow valve delivers water when you need it most Self seals after each sip and features a twist on/off bar to prevent leaks when not in use Dust cover protects silicone bite valve from collecting dirt Durable, high-grade compression molded silicone sheath Universal ¼ in diameter fitting Safe and reliable, 100% BPA & PVC free