Platypus Big Zip EVO Taste-Free Water Reservoir/Hydration Bladder, 2-Liter I bought these for a family hiking trip. But we only used them for the weekend. Like new! MaterialPolyurethane (PU), Polyethylene Item Weight0.6 Pounds About this item Premium taste-free, leak-proof reservoir with fast flow rate offers hydration on the go for hikers, backpackers, travelers and mountain bikers Secure SlideLock slides both ways to open reservoir easily and close it securely; handy pincher grip allows for easy one-handed filling The high mount quick-disconnect offers fast, easy access without having to dig down into a pack to attach or detach the drink tube Leak-proof shut-off valve instantly stops flow, stows reliably; HyFLO self-sealing bite valve improves flow along with large 5/16-inch drink tube To dry Big Zip reservoirs, first wipe the interioir with a towel, then prop the reservoir open with the SlideLock slider to let it air dry 2.0-Liter measures 8.7 x 15 inches and weighs 6 ounces; manufacturer’s limited lifetime warranty; made in the USA