●[Efficient Filtration] Double filter system with Hollow Fiber Membrane and Carbon filter. Hollow Fiber Membrane Filter Pore size: 0.1 Microns; Carbon fiber improves taste, removes odor, and protects the UF filter for longer life capacity. Life Capacity: Hollow Fiber Membrane 6000 L/1500 Gallons; Carbon fiber: 300L/80Gallons. Both filters are replaceable. ●[Large Capacity] With 1.5 gallons of large capacity, the gravity-fed bag can meet a familys or a groups water needs during your outdoor activities. ●[Ultra Safe Material] The gravity-fed water bag is made of food-grade, BPA-free, ultra-safe, and ultra-durable material to ensure water safe all the time ●[Versatile Uses]You can use the filter straw independently, or with a gravity water bag, or by adding an extension tube on the water straw for more distance, even connecting with water bottles. ●[Whats in the box] 6L water bag, Filter Straw, Adjustable Tree Strap, Detachable Tube