Premium Material The inner layer of this Hydration Bladder is constructed from PE material, while the outer layer is made of EVA material, providing wear resistance and corrosion protection. It is BPA-free, odorless, and non-toxic, ensuring safe drinking. Leakproof Design: This water reservoir bladder has successfully undergone pneumatic pressure testing, rendering it completely pressure-tolerant. The double sealing side technique significantly enhances durability. It features an automatic shut-off when the tube is detached, keeping the 2-liter water reservoir filled without leakage. Big Opening, Easy Filling And Cleaning: The wide opening is spacious enough for your hand, making it easy to clean the hydration bladder and fill it with water or ice cubes. This large opening allows you to reach every corner, ensuring a thorough cleaning of your water reservoir. 2L Large Capacity: This water bladder bag holds 2 liters, making it an excellent choice for outdoor activities, providing sufficient hydration for a day's worth of hiking, cycling, climbing, running, or biking. Measuring 34 x 17 CM, with a hose length of 100 cm, it is long enough for convenient drinking directly from your backpack. Perfect For Hydration Backpack: Compatible with most hydration packs, simply fill with fresh water and insert it into a backpack. To hydrate, gently bite the valve and sip as you would from a straw. Ideal for all types of outdoor activities, including hiking, cycling, marathons, camping, climbing, running, skiing, and jogging.