Cortech Super 2.0 18-Liter Strap Mounted Tank Bag 1680 denier ballistic polyester and 1800 denier three-lined twill Jacquard construction Protective non-slip, non-scratch diamond pattern mounting base Expandable main compartment increases bag storage capacity Locking zipper pull on expansion zipper One-way zipper on main compartment with a Zipper Garage for concealment Top flap internal organizer and soft lining Hideaway backpack straps Removable and replaceable snapped map pocket Hidden external pocket for eyeglass miscellaneous storage Phoslite reflective piping Two built-in sip tube/headphone exit ports Integrated stowaway rain cover, with clear window included Two-tone red and black soft lining interior Two-tone red and black soft lining shield pouch included Also available in a magnetic version Water bladder holder included