The VistaCruise is an aftermarket throttle lock, allowing the driver to free up the right hand from time to time. It's a big help on long hauls when your palm becomes compressed or pinched from squeezing the grip for so long, when your hand is sweaty, or you just want to rest your throttle hand for a minute. It also helps in the winter when you need to switch hand you're sitting on from time to time to thaw it out :-) .
Above is a good shot of the completed installation of the modified VistaCruise. You'll see the black collar on the grip, the little chrome strap is the friction ring, the thumb latch that is used to lock the throttle, a black bar that reaches across the control head (where the kill switch is located), and the 1" handlebar clamp located between the mirror bracket and control head. The VistaCruise is just above the starter button, so that's no interference there.
The VistaCruise is designed to work with stock grips, or those with a straight (non-contoured) grip body. I recently installed a set of Kuryakin IsoGrips and found that the VistaCruise wouldn't work with them. The IsoGrips have rubber pads along their length, and they have a flared flange on the end where the VistaCruise collar would normally be installed.
The basic installation instructions that come with the VistaCruise are usable, with the exception of modifications to these items:
Here is a shot from in front of the scoot, looking at the black throttle grip collar and chrome friction ring. You'll also notice the black 1" handlebar clamp installed between the mirror and the control head.