A durable and streamlined pair of Ortlieb Back-Roller Plus cases provide practical storage for those who prefer the convenience of a hinged lid closure system. Durable Cordura construction ensures waterproof Dust-proof and abrasion-resistant protection for the most demanding trips , and a removable shoulder strap makes it easy to transport when riding a bike is not possible. This durable case uses the QL2 mounting system. 1 allowing you to quickly and easily attach it to bike racks with tubes up to 16mm in diameter using self-closing hooks and there are also special inserts to reduce the size of the hook for tubes with a diameter of 8 mm , 10 mm and 12 mm. Besides 3M Scotchlite reflectors improve your visibility to motorists at night.