The osprey ultralight stuff bag is a lightweight backpack thats ideal for short journeys and simple loads once you have finished your ride you are able to stuff the bag away into its own carry case which is no larger than the size of an apple built with a deluxe airmesh harness the backpack offers a comfortable carry unusual for a compressible pack of this size fully waterproof coated fabric and seams mean you wont get caught out in the event of a light drizzle or sudden downpour for organ