Bulletproof Messenger Backpacks are designed for for those who prefer the double strap support of backpacks, but still want the durability and weatherproof attributes of messenger bags. These backpacks are made tough with military spec. seam binding, 1000d Cordura shell, 18oz. weatherproof truck tarp liner, and a nylon 69 thread. They are tough and include independently suspended weatherproof liner which freely floats within the outer shell eliminating seams exposed to the outside elements. The beefy EVA foam shoulder straps and a molded back panel makes them really comfortable even for long rides. Three styles, all which come in a variety of different colors, include the Backbone(large), Ranchero(medium), and Dually(small).