For folks planning to travel with their hiking, backpacking or trekking pack, the AirCover does double duty as a durable cover with a zip-back closure to fully encase and protect your pack on the bus, train or plane and doubles as a raincover when you hit the trail. Comes in two sizes to fit most packs. Medium fits packs 40-60 litres in volume. Large fits packs 60-75 litres in volume. Get your Osprey Aircover Medium Black Universal. Part of a coordinated system for optimised packing; Customise your experience by adding on smart packing and organisation accessories that meet your exact needs. All of our accessories have been overhauled to offer better organisation, operation, comfort and reduced environmental impact. Includes bluesign approved main body fabrics, GRS-certified 100% recycled main body fabrics and DWR treatments made without PFAS. Packs into itself. Includes draw cord to adjust fit.