Jack Wolfskin Rock Surfer 30.5 Bike Backpack style:1.shell: 100% polyamide; 2.shell: 100% polyamide; lining: 100% polyester Imported 3.15" high 12.2" wide Large, fully-featured bike pack with flexible suspension system Dual-chamber bike pack Main compartment and base compartment, 8 pockets Helmet attachment, stowaway waist belt, attachment for LED light, rain cover, bike organizer Equipped for a hydration system