3V Gear 3.0 Liter Top Fill Hydration Bladder for hiking, tactical, hunting, backpacking, camping and sports 3.0 Liter; Metallocene PE high strength & taste free film (BPA, Latex & PVC free) Tough construction for maximum abrasion resistance Anti-microbial bladder interior and drink tube to prevent bacteria and mold Top Fill opening for easy fill and cleaning Patented bite valve on/off twist design