PSI makes three "crank-trigger" styles (radial, inboard support, and standard), and one non-crank-trigger style. All are black anodized with engraved degree markings for improved visibility of the lines while setting your ignition. The timing marks are in one, five and ten degree increments; the 90-degree increments are omitted so you can find the group that matches with your particular pointer and scribe it yourself. An added feature is that all PSI degree wheels attach to the crank hub with a double bolt and pin pattern. This allows you to rotate the degree wheel to realign it if you switch crankshaft brands.