MATERIAL: The water bladder is made of PEVA material, which is wear and corrosion resistant, and does not contain any harmful ingredients EASY TO CLEAN: The water bladder has a large top opening , which is convenient for water injection and cleaning EASY TO DRINK: Open the dust cover, lift the mouthpiece and suck it in to drink, then push it back to lock it PRACTICAL: The water bag is compatible with most backpacks. Can withstand temperatures from -20 to 50 degrees Celsius USES: The hydration reservoir is perfect for outdoor sports such as marathon, running, hiking, cycling, camping