15L backpack. Fabric on the sides, front and top are waterproof. Front pocket with waterproof zipper w /reflective film. Strenghthening fabric on bottom and neophrene on back for breathability. Adjustable shoulder straps and hook. Two buckle closing. The inside lining of the bag is quilted so it is perfect for storing a computer, cameras or other delicate items. It is of course also great for storing food packs, extra clothing or simply books. The bags measurements are 40cm x 35cm x 10cm. Fabric in black backpack: Techmaflex: 55% Polyamide, 45% Polyurethane. Fabric in blue and green backpacks: 66%PVC, 22%Polyester, 12% Polyurethane.