Osprey Transporter Waterproof 18 Liter Day Pack - If your adventure is bound to be wet, the Transporter Waterproof 18 is better than water off a duck's back. Its IPX6 roll-top closure keeps the elements out while simple internal organization keeps up to 18 liters of gear inside and in place. Osprey has applied the comfortable AirScape backpanel, giving you a more stable carry. By foot, bike, board or boat, keep your gear dry with the Transporter Waterproof 18. Made with 100% recycled materials.