Peregrine Summit Ultralight Day Pack 30D CORDURA Ultralite fabric delivers a desirable combination of qualities: durable, compact, lightweight and weatherproof YKK zipper runs along the top and down one side for sufficient access to the inside Double waterproof treatment with a siliconized outside and a polyurethane coated inside; Taped and double stitched seams keep the bag watertight Siliconized outside and a polyurethane coated inside deliver long lasting weatherproof qualities