How it Works - The Single Superchock is Self-adjusting !
1.Put your thumbs in the thumb-holes of the re-cycled plastic chocks and grip the 2 chocks. 2. Pull the 2 chocks to expand the connecting bar. 3. Extend the connecting bar wide enough to allow the re-cycled plastic chocks to go on the outside of the wheel. 4. Release the chocks and the spring tension snugs the chock to the wheel.