While regular Back Roller panniers have a volume of 40 liters per pair, the Pro version amps things up by a couple of notches. - 100% waterproof: these panniers are all the rain protection your gear needs - Welded seams - QuickLock 2.1 system grips your bike rack instead of just hanging on it - The lock system is adjustable without tools - Large, high quality reflectors front and rear - Roll closure: super reliable, fast and light - Flat inner pocket with zipper - Front pocket on each pannier - Shoulder straps included in price - 5 year guarantee Volume: 2 x 35 = 70 liters when rolled shut for water protection. Weight and volume refer to a pair of panniers. Measurements refer to a single pannier.. By adding one of this product in the shopping cart, you receive a pair of bags