Take the Ortlieb Rack-Pack on bike tours, trains, motorcycles and plane rides. No matter where you are, on foot or on wheels, your Ortlieb Rack-Pack can come with you. The versatile pack is completely waterproof and opens wide with a horizontal rollnsnap catch. Use it as your gym bag or throw it atop your panniers and go for a ride - either way, you can feel confident that your contents will be safe and secure. The durable pack holds what you need, and can be rolled into a tube to comfortably fit on the rear rack of your bike or on top of your bike trailer. The roll closure has a stiffener bar, so closing the bag while assuring 100% waterproofness is very easy. The Medium Rack-Pack holds 31L and, like the small pack, connects easily to the Ortlieb Roller Series panniers using the durable buckles; creating an interlocking combination of rack-top cargo. The shoulder strap allows the bag to be comfortabley carried around the camp or to the gym. Rack-Pack Medium Material: PD620 Volume: 31L / 1892 cu.in. Size: 11" dia. x 21" long Weight: 760g / 26.8 oz. Rack-Pack Large Material: PD620 Volume: 49L / 2990 cu.in. Size: 14" dia. x 24" long Weight: 910g / 32. oz. View Rack Pack Specs