The Mission Workshop expandable freight knapsacks feature a waterproof primary compartment which can be used in either “roll-top” mode, or in the standard “flap-down” configuration. An essential function of the Cargo Packs are their capability to rapidly double in size when needed for extra cargo carrying capacity. Made in the U.S.A. with a lifetime warranty.
More Here: http://missionworkshop.com/products/bags/backpacks/
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