A loading dock is an architectural fixture where trucks may be loaded and unloaded. They are commonly found on large commercial and industrial buildings. Warehouses that handle palletized freight use a dock leveler so items can be easily loaded and unloaded using power moving equipment (e.g. a forklift). When a truck backs into such a loading dock, the bumpers on the loading dock and the bumpers on the trailer come into contact and create a gap; also, the warehouse floor and the trailer deck may not be horizontally aligned. The most common dock height is 48” – 52”, though heights of up to 55" occur as well. A dock leveler bridges the gap between a truck and a warehouse to accommodate a forklift.