Professional 16" Diameter Machined Aluminum Camshaft Degree Wheel Machined from 1/4" thick aluminum plate. Red anodized and precision engraved. Open design allows camshaft degree bushing changes while the wheel is still on the engine. This extreme precision tool is found in most NASCAR shops and is a must for any professional racer or engine builder. 1" center hole allows wheel to work with COMP Cams crankshaft sockets