This is a well made water bladder,made of thicker TPU,it is strong,sturdy,tough but light; it has the wide opening, easy to open and seal with the sliding locking; Quick release tube connector, and the center baffle keep water bladder flat and stable even at high speed, its smart and sporty looking;Perfect fit for most standard hydration vests,a convenient way to stay hydrated on-the-go, perfect for handsfree hydration while you engage in hiking, running, cycling, skiing and more;