Aurosports Hydration Bladder 2 Liter - Water Storage Bladder for Hydration pack System Professional military Bladder Bag,Eco-friendly TPU material,100% odorless, tasteless, BPA- Free material. FDA APPROVED: Food-grade premium quality anti-bacteria materials. Thick TPU bladder material is pressure-tolerant and wear-proof. 3.54 inch openings. Large opening for easy cleaning and easily adding ice. Strong elasticity, not damaged. When filled with water, can withstand squeezing. Can withstand the water temperature range: -20 to 50 degree Celsius. High-flow bite valve with dust cover. mouthpiece with a valve switch, to prevent leakage. - Lifetime Guarantee.