Our largest bag, with a pocket and a bottle-pouch at the back, a zip-up pocket inside and three elasticated net pockets around the outside to stow things for the ride, as well as a roll-top system with nylon clips for closing. Capacity approx. 31 litres; dimensions 420w x 300h x 270d; supplied with a shoulder strap, high-visibility rain resistant cover and front carrier frame. A front carrier block is not included when ordering this item. If you only want one bag for your Brompton, this is the one.