Starting on the inside, a 0.500" oversized steel shaft spins in a sealed ball bearing and sintered bushing for long endurance and accurate spark delivery throughout the entire rpm range. Mounted on top of the shaft is an easy-to-adjust chro-moly mechanical advance assembly. Different advance springs and stop bushings are supplied so you can choose from 24 curves. A maintenance-free magnetic pick-up provides accurate trigger signals to your MSD Ignition Control. A precision-manufactured reluctor that is connected to the shaft is responsible for triggering the pick-up. The distributor is topped off with a high quality black cap and Race Rotor.