Buyers steel underbody toolboxes are constructed of 14-gauge high quality American stainless steel. The 12-gauge steel door features crossbar reinforcement to shield the locking mechanism from bumps without limiting storage capacity. The flush mounted door has a pitched top lip design to avoid water collection, and the 1/2" automotive style door gasket forms a continuous seal to keep the elements out. The recessed T-handle and flush-mounted door gives this box a sleek look and creates minimal wind resistance when you're on the road.