The BikeMaster® Aluminum Timing Degree Wheel is made from durable, thick, 6061- aircraft aluminum sheet. It is 7″ in diameter with large, highly visible markings. Lightweight and coated with a durable finish, it can be used for crankshaft positioning, ignition and camshaft timing Lightweight design with a durable finish, suitable for ignition, camshaft, and crankshaft timing 7″ diameter with large, highly visible, and precise markings for accurate timing