This is not a true cruise control, and works best to give your hand a brief rest, and also allows you to maintain speed using just the pressure of your palm on the grip. This is the method I use, and it has done many 500-600 mile days. See How-To install the vista cruise Throttle lock, on the VOAi web site for instructions and optional ways to install. This unit is a more sophisticated form of throttle lock. And uses a twist of the end knob to lock the throttle setting in.
Package comes with matching right and left grips.
Requires removing old grips on both sides, so install somewhat harder than the vista cruise. Based on comments from other members, works very well. Do it yourself Cruise Control. Several have followed his directions successfully. This is a kit that offers true cruise control.