The product is a stiff piece of plastic designed to slip over your throttle grip. An adjustable aluminum version is also available.
To install takes just a few seconds - you spread the grips wide enough to slip over the grip, near to the inner edge of the grip, then push it into place.
Once in place, it holds the grip securely, pointing forward:
When the throttle is opened, it rotates back with the throttle.
To use the GoCruise, you open the throttle normally and allow it to rotate back with the throttle.
When at the speed you wish to maintain, you use your finger to push the GoCruise down against the front brake lever.
The GoCruise holds the throttle open, using the leverage against the front brake lever. Brake operation is unaffected. To disengage the throttle lock, just roll the throttle off normally, and the GoCruise slips under the grip and returns to its normal position.
If you have a slightly smaller diameter grip, or find the GoCruise slips, it comes with a silicone ring that you can install over the grip before installing the GoCruise, that increases the diameter of the grip slightly.
So, how does it work? Amazingly well. It fit my wife's bike perfectly. She figured out how to use it within a minute, and she reports that she loves it. If your bike doesn't have a cruise control or a throttle lock already, this little device is well worth the meager price they sell it for ($19.95). It comes in two sizes, small (for 7/8" diameter handlebars) and large (for 1" diameter handlebars). If you like lots of bling, they have a chrome version, as well. For more information, or to purchase, visit their web site at http://2wheelride.com.