This internal throttle control allows you to route a single throttle cable inside the handlebars for those classic, naked looks as found on most Harley's built before 1974. Fits all 7/8" (22mm) and 1" (25.4mm) diameter handlebars. Must be used with a left side OEM or aftermarket grip.Requires cutting off about 4" of the handlebar, as well as drilling holes. Does not work idle cables.