Checkers 4600 series military aircraft wheel chocks are an updated version of the traditional wooden military chocks. These new composite urethane wheel chocks weigh less than wood chocks and are resistant to the aircraft fuels, hydraulic fluids and lubricants used in the aviation industry. Tigerchocks will last years longer than wooden chocks, never need painting and are not potential foreign object damage (FOD) problems for aircraft. Standard with 5/8" x 36" or 48" replaceable nylon rope lanyard. These chocks utilize the Tigerchocks rope lock system. This original military style chock-to-chock rope lock system allows a wheel chock to be temporarily and securely attached to the opposing wheel chock on the opposite side of the aircraft tire. This chock-locking system ensures that wheel chocks remain firmly positioned against each side of the aircraft tire during engine test procedures. Weight: 7 lbs. Measures 14" length by 6" width by 4" height. Molded in high-vis yellow color.