Large expandable storage bag with waterproof main compartment and drop down panniers for extra storage. Integrated water bottle/drink holder and included shoulder strap add to the convenience factor. RF seam sealed inner liner and waterproof zipper on main compartment. Universal and durable trunk bag with plenty of space for your belongings. Front and bottom straps securely attach the bag to the rack. Reflective side and rear accents for improved visibility and safety. Side zipper pockets for additional storage. Handle on top for carrying while off the bike