ORTLIEB Velocity PS Backpack - 17L A safe and secure way to carry your kit, the 17-litre ORTLIEB Velocity PS Backpack is versatile enough for sports, commuting or college, and has a sturdy, protective construction. The bag is made from a sustainable PVC-free, PU-coated nylon that's fully waterproof, with protectors over the lower edges to prevent scrapes and knocks. A roll-top closure with hook and loop straps not only makes it easy to pack the bag but also guarantees water cannot get in anywhere. Internally there are 17 litres of storage space that includes a zipped organiser and laptop sleeve for computers up to 15". A key feature of this bag is the foam back padding that cushions while increasing ventilation, making for comfortable carrying. The fit can be dialled in by the adjustable shoulder, waist and sternum straps, and the latter two can be removed when not in use. A strap on the outer back means you can carry a helmet or clip on a light, and there's a carrying handle for when the bag's not on your back.