Milwaukee Twins Speedo Drive Unit For Harley Sportster / FX Milwaukee Twins Replacement Speedo Drive Unit can be used with a variety of 2:1 ratio speedometers or when converting away from electric speedometer. The drive unit has an .750 axle hole, and includes a .361 wide spacer with an overall length of .940. This mechanical gear drive replaces the stock unit mounting to the wheel without modifications. Features: For 2-to-1 ratio speedometers, or when converting away from electric speedometer The drive unit has an .750 axle hole, and includes a .361 wide spacer with an overall length of .940 Replaces OEM 67127-84 A