Introducing the Big Zip EVOthe latest evolution in taste-free hydration. The Big Zip EVO delivers a significantly higher flow rate than previous Platypus reservoirs and a host of new features, making it a great option for backpackers, hikers, and mountain bikers. Available in 1.5L, 2.0L, 3.0L and a Lumbar 2.0L.\r\n\r\nSecure SlideLock: Slides both directions to easily open, securely close and fill reservoir.\r\nHandy Pincher Grip: Allows for easy one-handed filling.\r\nHigh Mount Quick-disconnect: Offers fast, easy accessno more digging down in your pack.\r\nLeak-proof Shut-off Valve: Instantly stops flow and offers reliable stowing.\r\nSemi-rigid Center Baffle: Offers low-profile support and makes for easy cleaning and drying.\r\n\r\n\r\n\r\nHyFLO Self-sealing Bite Valve: Improves flow along with new, larger 5/16\