WBM Sander Boxes are built with 10 gauge Corten corrosion resistant steel, while the mainframe is built from 3/16″ corten steel. It is structurally designed to withstand the weight of a full box of material when dumping. When accompanied with the hoist cylinder (optional), material can be dumped out the rear of the box through the manually bolted rear tailgate. Also included are a manual crank discharge gate opener, 24″ discharge chute, rear pivot blocks, hopper lifting lugs and a 25:1 gearbox for the conveyor chain operation.