This Ultragard luggage rack bag is made with high quality weather resistant materials, durable construction, and a sturdy mounting system. A large main compartment allows for maximum storage. Four additional easy access zippered compartments,and two expandable side pockets add up to 3,320 cubic inches of extra storage space on your bike. Also included are a rain cover and comfortable shoulder strap.20" x 10" x 8.5" (51cm x 25cm x 22cm), main compartment 3 mesh pockets 2 expandable side pockets.