ISO THROTTLE BOSS BY KURYAKYN MFG# 6250
Source: Custom Chrome
Added to the popular KüryAkyn"! 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 one's throttle hand. This allows the driver to slightly relax the grip on the gas and still maintain a constant speed. Muscle stiffness and fatigue are reduced after prolonged cruising at a steady pace.