Odorless and high-quality materials for greater safety: The replacement hydration backpack for the outdoors is made of high-quality antibacterial materials. Food grade TPU material and TPU tubing make the hydration backpack safer. Odorless, non-toxic, BPA free and FDA approved. The water tank has been tested under air pressure and is fully pressure resistant. Double-sided sealing technology for greater durability. Large capacity 2 liter water bag: the 2 liter water bag is designed to fit most backpack sizes . You can use it for your outdoor activities: hiking, running, cycling, skiing, riding, camping, cycling, climbing, etc. This is a must-have item for sports enthusiasts and an ideal gift. Large opening for easy filling and drinking. The 2 liter water bladder has a large opening for easy filling. This 2 liter water bladder can withstand temperatures ranging from -20 to 50C. To get cold water, just add ice cubes directly from a spoon or from the refrigerator's ice maker. The TPU tube is flexible and more resistant to bending, making it easier to adjust when drinking. Waterproof and ergonomic - the military-grade hydration reservoir has been fitted with A military-grade waterproof thread around the edge to ensure that the 2 liter tank is pressure and water resistant. The bite valve has an on/off switch. Just bite the mouthpiece to absorb the water. The dust cap protects the tip from dust. Just pull the valve up to drink and push it down to close.