Heavy gauge Tool-Tra-Top. Back-up plates reinforce all top connectors. Slip-resistant Traction-Tred steps are double riveted and knee-braced. Shoe pads riveted to the edge structure. Aluminum external rail shield helps protect against abrasion damage. The edge bracing system helps to decrease damage to rail. Glas Mark violator strips on rails allow ladder to be more visible. Full set of rear horizontals are knee braced and spaced one per foot. Extra heavy duty internal spreaders. Shoulder bolt and lock nut on tope hinge. 4 solid aluminum rivets attach top to each front rail. Every rivet backed up by metal part or washer to protect rails. Dimensions: Front rails 3-1/8" wide, front flange 1-3/16" wide, rear rails 1-7/8" wide, rear flange 1-3/16" wide, top 7-1/4" wide x 14-7/8" long, steps 3" wide. Meets ANSI and OSHA Standards.