These patented harmonic balancer covers offer improved readability, more stable Top Dead Center indication and timing accuracy, enhanced appearance for a previously ignored underhood area, and the elimination of timing tapes which are inevitably flung off. They are available in chrome and black, resulting in parts with the appearance of $200 balancers. Each cover is distinctively marked with Top Dead C enter and the proper timing degrees. Using this cover improves timing accuracy because over time the etched outer inertia ring of a typical harmonic balancer may slip in relation to the center hub of the balancer, causing the etched markings to provide an inaccurate indication of Top Dead Center for the #1 piston. Mounted directly through the center hub, this cover eliminates the affect of any outer inertia ring slippage. Aluminum. U.S. Patent 5,675,078