The EVERFUN hydration backpack weighs 1.7 pounds and has an 18 liter main compartment with a 10.5 inch opening, an interior mesh pocket, a velvet-lined upper pocket for a phone, side mesh pockets and a helmet carry. The included 2 liter bladder is BPA free and replaceable, and its insulated compartment keeps water cool for about 6 hours with ice packs. The high-density nylon pack has a built-in rain cover and reflective strips.