Marson USA 5.5" Motorcycle Wheel Chocks #T200-B Chock Constructed of 1" heavy duty steel tubing and black powder coated for a sharp appearance. The same chock with extra side supports is available - please search: T200-HDB Chock Blk Dimensions: Exactly 8.25" wide at the opening and 5.5" wide at the start of the radius x 9.25" high. 3/8" hex head sleeves and phillips pan head bolts are 1" long. * Mounting bolt hole pattern: 5.5" side to side on center. 5" front to back on center.