Introducing the Big Zipâ„¢ EVO 2.0L Reservior which is the latest evolution in taste-free hydration from Platypus. The Big Zip EVO delivers a significantly higher flow rate than previous Platypus reservoirs and comes with a whole host of new features, making it a great option for backpackers, trekkers and mountain bikers. Platypus Big Zip EVO 2.0L Features: Secure Two Way SlideLockâ„¢ Opening Handy Pincher Grip for One-Handed Filling High Mount Quick-Disconnect Leak-Proof Shut-off Valve Semi-Rigid Centre Baffle HyFLOâ„¢ Self-Sealing Silicone Bite Valve Embedded Silver-Ion Protects Against Mould and Bacteria. Certified Taste-Free, BPA-Free, BPS-Free, and Phthalate-Free 2 Litre Capacity