A wheel chock is a simple wheel holding device - shaped like a small ramp - and often found in automotive workshops, those that use RV's and motorcycle owners. They're especially also useful if you haul a trailer, whether it's a few days break or for longer periods.
In the automotive industry, they're most used for when a vehicle has a rear wheel braking system. If the of the car is lifted up, the safest way to prevent injury is to simply insert a tire chock - which will hold the vehicle steady and stop it from rolling.
The five best wheel chocks are featured below. Popular and best selling, they're also good value for money, largely inexpensive and highly rated by previous purchasers.