The ortlieb back roller plus ql21 is both a commuting and touring favourite the back roller plus uses a lighter weight cordura finish fully backed by a laminate which is more eco friendly and expensive than the heavier arguably tougher pvc versions the design of the bag is really simple and the name of the bag is based around how the bag closes shut they roll up with a single clip and strap holding them shut its basic but it works very well the roll prevents water from getting throug