The CrampBuster provides a way for comfortable throttle control & dramatically reduces the wrist fatigue often caused by long rides. The CrampBuster will rotate forward all day long. Yet when downward pressure is applied by your hand, the throttle is regulated effortlessly & accurately without squeezing.The CrampBuster provides a way for comfortable motorcycle throttle control and dramatically reduces the wrist fatigue often caused by long rides. It is not a cruise throttle lock, but rather a cruise assist. No tools are required for installation. Just spring it open and slip it on.STANDARD SIZE: Fits motorcycles with 7/8" bars using 1-1/8" to 1-3/8" O.D. grips.OVESIZED SIZE: Fits motorcycles using 1-7/16" to 1-3/4" O.D. Grips