420 Denier Nylon and 600-Denier Polyester, The Semi-Pro Sports Bag with Water Bottle Holder is the perfect balance of durability and storage. Built to last but not packed full of unnecessary features that drive up the price. Constructed of both nylon and polyester, this bag will be ready for you, even when you may not be. There is even a front pocket and convenient insulated water bottle storage spot for easy access.