Bluff heavy-duty aluminum dock plate lightweight aluminum dock plate has integral handle holes for easy lifting and a slip-resistant diamond tread surface. Beveled entry and exit edges, 11 apron and 11 degree crown angle offer a smooth transition between truck and dock. Safety stop, located on underside, helps secure the dock plate in position. Not for use with rider type trucks. Note that the width should be 12 inches wider than the load. complies with osha spec. 1910.30a and ansi spec. Mh30.2 ** ht. difference is the height difference above or below the dock.