Used to prevent commercial vehicles from rolling at the loading dock Helps prevent accidents and comply with OSHA 29 CFR 1910.178(k)(1) ? Powered Industrial Trucks:1910.178(k) Trucks and railroad cars. (1) The brakes of highway trucks shall be set and wheel chocks placed under the rear wheels to prevent the trucks from rolling while they are boarded with powered industrial trucks .Extra-heavy-duty laminated rubber construction is virtually indestructible and backed by a manufacturer?s 5-year warranty: Guaranteed to be free of defects in material and workmanship under normal conditions of usage, provided the manufacturer?s recommended installation and maintenance instructions are followed1/4" thick structural steel clip with 3/4" hole can be used to tether to a dock for safe keeping (chain not included)Contoured shape design fits most commercial truck/trailer tires Constructed of laminated rubber pads woven on ?? steel b