The Blackhawk A.L.E.R.T. 5 Bag is the largest loud out back offered! The Assault Load-Out Emergency Response Transport or Trunk (A.L.E.R.T.) Bag is constructed of multiple layers of 1000 denier nylon with reinforced stitching for durability. It features compression straps to stabilize load (two for external compartment and three for main compartment) and large, U-shaped, hinge-type lid for easy access.