This water bag comes with a BPA free 3L water bladder. The bladder itself has a well made lid that screws on tightly and doesn’t leak even with a lot of pressure. The MOLLE system allows you to carry more items. The adjustable shoulder waist and chest straps are good for keeping the pack from flapping around. This tactical hydration pack backpack is the best choice for short trips, running, cycling, hiking, skiing, camping, hunting, scout. A great gift for friends and family who enjoy outdoor sports.