Unlike most shift knobs on the market, Rennline’s are far from “universal”. Universal usually means that it will nearly fit some applications and will not fit the rest. All Rennline shift knobs are CNC machined to fit specific applications, eliminating the concern of missing a gear due to loose or detached shift knob. There is no need to cut, drill, or modify your factory shift lever to install. All of our shift knobs are the ergonomically correct 1.875” diameter and have rubber trim rings installed at the base. Available in Silver and black finishes, for cars with or without integrated shift boots. 911/912/930 1965-1986 87-89 w/ manual transmission . * on 87-89 cars, please measure shifter shaft to ensure fitment as several shifter shafts were available through those model years. The hole in our knob measures .595"