Equip your semi truck to be Ready for the Road Ahead , with the Power Products 9 Lb Wheel Chock, a key component that locks vehicles, trailers, and RVs in place. This replacement device works to prevent vehicle movement when parked, removing the worry of a runaway truck or load. Engineered with a pyramid shaped design to work on both front and back tires. FleetPride is your First Click in Heavy Duty .