Hydro Flask Soft Cooler Backpack Unbound Series 15L Brick Gray Orig $225! NWT! The Hydro Flask Soft Cooler Backpack Unbound Series 15L in Brick Gray is a versatile and portable option for keeping your food and drinks cool while on the go. With three compartments and a 15L capacity, this backpack is perfect for outdoor activities like beach trips, fishing, traveling, camping, and hiking. Made from durable nylon and plastic materials, it is lightweight at only 3 lbs and features a compact design with dimensions of 10 inches in depth, 19 inches in height, and 13 inches in width. The brand's reputation for quality and the sleek design make this cooler backpack a must-have for any outdoor adventure.