The Osprey 20 & 30-litre Dry Sacks are designed to keep clothing, footwear or other essential items bone dry inside a travelling bag or backpack. These sacks are made of a coated 40D nylon ripstop with sealed seams, making them sufficiently waterproof. They have waterproof and secure roll-top closures, packable rectangular shapes, and come in a range of bright colours for easy organization inside a backpack or duffle bag.