Will you Fight or Flight? Pack up for anything this world throws at you. Our Fight or Flight Packs are made of durable canvas material and reinforced canvas on the bottom to keep your pack from giving up when you need it most. A water bladder can be added to the reinforced canvas sleeve in the main compartment and/or a bullet proof plate. Theres a slit cut at the top for your water bladder hose to be fed out of for ease of use. Only available in OD Green.