|By extending your ATV throttle and providing multiple thumb positions, these handy assists provide more leverage while using the palm of your hand to apply the throttle. This virtually eliminates a tired or sore thumb after a long day of riding. They have a comfortable ergonomic shape and non-slip surface. Fits all ATVs without modification to the existing throttle tab. Installs in minutes. The Thumb Assist™ Pro Adjustable offers the added versatility in placement for your riding comfort. Lever adjusts toward and away to optimize control for riders with hands of any size.