ORTLIEB Velocity PS Backpack - 23L The messenger daypack is a favourite in the ORTLIEB range, and this Velocity PS Backpack, with a 23-litre capacity, is ideal for those who want to do away with the shiny tarp look of the classic Velocity. A versatile choice, the Velocity PS is well suited to commuters and students, for sports, work and everyday use. Constructed from a sustainable PVC-free, PU-coated nylon, the bag is sturdy and waterproof, with lower edge protectors that prevent scuffs and excess wear. There's plenty of space for essentials, and the design includes a zipped organiser with a laptop sleeve for added protection. A roll-top closure with hook and loop strap guarantees no water will get inside the bag, so the contents stay safe and dry. Carrying is comfortable thanks to the foam which enhances ventilation, and the shoulder, waist and sternum straps are all adjustable to dial in a perfect fit. Additionally, the waist and sternum straps can be removed so there's no flapping when they're not in use. An external strap allows you to securely attach a light or helmet.