Buyers Products Black Steel Underbody Truck Box w/ Aluminum Door (18X18X36 Inch) Dimensions: 18"(H) x 18"(D) x 36"(W) Powder-coated diamond-tread aluminum door adds a high level of corrosion resistance to the part of the box that is most exposed. Black powder coating helps keep the box corrosion-resistant. Can be mounted on either a flat surface or under-bed. Built for long life with aircraft-grade cables and a replaceable gasket sealing system.