A continuous grooved design in the heavy duty rubber creates a secure grip against tires. A wide metal handle is attached directly into the chock, making it easy to carry or tether to a secure spot for safe keeping.Use to meet federal regulation Occupational Safety and Health ...A continuous grooved design in the heavy duty rubber creates a secure grip against tires. A wide metal handle is attached directly into the chock, making it easy to carry or tether to a secure spot for safe keeping.Use to meet federal regulation Occupational Safety and Health Administration 29 Code of Federal Regulations 1910.178(k)(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.