Kuryakyn 6242 ISO Extended Throttle Boss 1/4" Longer Than Standard ISO-Throttle Boss Added to the popular Kryakyn ISO-Grips, this little jewel can make all the difference in the world on a long ride. The Throttle Boss is a small adjustable paddle that is positioned under the palm of the throttle hand allowing the driver to slightly relax their grip on the gas and still maintain a constant speed. Kuryakyn part # 6242 Note: ISO-Grips for use with GL1800 Heated Grips (P/N 6183) will only accept Extended ISO-Throttle Boss (P/N 6242) or New P/N 6310. Not compatible with HD