An AquaSafe flood bag is stored dry, and measures only 1 inch thick and weighs less than 1 pound. When activated, by absorbing liquid, it will expand to 6 inches thick and can weigh up to 50 lbs. AquaSafe primary materials include: hydrophilic (absorbs water), extremely durable needle punched polypropylene (competitors use spun bond polypropylene) porous texture for quick absorption, strong cross-stitched seam for total containment and SAP (super absorbent polymer) blend.