Ortlieb Back Roller Classic is an easy to use pair of panniers for your bike's rack. The material is 100% waterproof and all seams are sealed for complete water protection. - QL2.1 mounting system holds the panniers securely; the panniers do not simply hang on the rack - Roll-up closure - Quicklock and well adjustable attachments - Shoulder strap - Flat inner pocket with zipper - Reflectors - Welded seams - Five year guarantee The material is easy to clean. Volume: 2 x 20l=40 l, if the mouths of the panniers are rolled enough to keep them waterproof. You can gain extra space at the cost of water protection by rolling the top fewer times. Weight and volume refer to a pair of panniers. One package contains two panniers, one for both sides of the bike.