ROLLER BEARING ADVANCE UNITSpecial roller bearings at the pivots of the advance weights gives the proper amount of ignition advance at the right time every time. This quality kit includes the roller bearings installed on a quality advance unit shaft and plate, circuit breaker base plate, points cam, wiring harness, springs and timing screw. Fits 1970 thru 1978 Big Twin and 1971 thru 1978 Sportster models, as well as all later models when converting to point style ignitions.