Odorless Material, Insulated Tube All parts of the hydration pack are made of BPA-free and FDA certified food grade material. Military water bags are thicker and more durable. The material is smooth inside to keep the water clean. The water bladder adopts high quality TPU drinking tube, which has no peculiar smell. An insulating sleeve has been added to reduce temperature variations in the flow of water from the hydration reservoir through the tube. Leak-proof technology, quick-release tube The hydration bladder tube is easy to connect and disconnect with one hand. The stop valve will close automatically and there will be no leakage if the hose is not connected. You can easily and quickly refill your 2l hydration pack without the tube attached, without worrying about it leaking everywhere. We applied the highest military-grade double-sided sealing technology on the insulated hydration bladder to ensure that the entire hydration bladder is leak-proof and pressure-resistant. Innovative bite valve, high-flow waterThe water bladder with 90 angle bite valve helps you drink plenty of water quickly with every sip. You just need to slightly bend the tube to put the mouthpiece in your mouth. The smaller bend angle allows the water flow to work more efficiently. The bite valve has a push/pull design that allows you to stop flow when not in use and easily pull with your teeth to restart flow. A cover keeps the mouth of the reservoir clean on the outside. Large opening for easy filling and cleaning The 2 liter hydration opening is large enough that you can fill/refill water very easily even without taking it out of the hydration bag. You can also put ice cubes in the water bag to keep the water cool. The large opening allows you to reach every corner of the interior and clean the tank thoroughly. Therefore, you can always keep your drinking water bag very hygienic. Notes: Dear Buyer. The size is manually measured, the unit is CM, there is an error of 1-2MM, please refer to the actual product. Photos are taken in kind. There will be slight chromatic aberration due to shooting light, angle and monitor. Please refer to the actual item received. Each product is inspected before shipment. Please rest assured to place an order. Pieces: 1 Colour: green Size: 3L