"The Black Widow Deluxe Motorcycle Wheel Chock is designed for optimal stability and ease of use. This wheel chock can be used as a free-standing floor stand, or it can be mounted to a flat surface with your choice of hardware (not included). Incredibly user friendly, simply ride your bike into the chock and the cradle locks it into an upright position for easy maintenance and storage! With nine adjustable positions, this chock accommodates tires from 8"" to 16""."