This 11-inch diameter Degree Wheel has color-coded scales for instant read-outs. Made of sturdy aluminum and designed to read the same as the camshaft spec card reads, it is precision degreed for accurate readings. The exhaust and intake centerline areas are also indicated and color-coded. Claimed to be the best wheel on the market, it also fits many blowers. Universal design fits 7/16 ", 1/2 ", 5/8 " and 3/4 " crankshaft bolts. Fits most Chevrolet, Chrysler and Ford engines.