Curt Manufacturing wheel chocks are a piece of excellent equipment to have in the vehicle for towing and maintenance. Choking the wheels is a must whenever you get the car or truck to change oil, do maintenance, or make repairs. Even if you're merely checking fluid levels under the hood, it's a good idea to double-check that the vehicle isn't moving. Similarly, use wheel chocks whenever the vehicle is hitched to a trailer and parked for a long period, whether at a campsite or on a boat dock. The wheel chocks assure that the towing rig does not roll away without you in the driver's seat. The parking brake of a car should never be the sole thing used to hold the weight of the vehicle and trailer in place, particularly if it is parked on a slope. Curt wheel chocks are engineered to be used with the vehicle's handbrake to stop it from rolling. The wheel chocks are made of tough plastic and have a wide 17-inch width. It can be used with a wide range of wheel and vehicle sizes. As a result, however, it must never be used for commercial purposes. Curt wheel chocks also include a raised tread for enhanced wheel grip and saw-tooth edges on the base for improved ground contact.