I use them on timber sled snow bike , work great hands never cold , on high they hit 114° when it's 12°out side .
These grips went on an '00 VFR800. Both grips and the controller have connectors between them which makes installation a cinch. I used a universal 12 volt relay from an auto parts store between the battery and the grips and set it to switch on with the license plate light. This means that the grips only receive power when the ignition is on, preventing a dead battery if I forget to switch them off.
The grips themselves are very thick, over twice the thickness of the OEM grips. If you have small hands you might need to adjust your levers a little closer. The heat from the grips is excellent, they keep my hands toasty on a medium setting even through winter gloves. The heating element is integrated into the grip unlike the cheaper grip heaters that go underneath normal grips. There is insulation between the heating element in the grip and your handlebar, so these are suitable for aluminum bars that might draw all the heat away from other types of grip heaters.
The inside of both grips is hard plastic, if your throttle tube has ridges you'll need to shave/file/grind them smooth, then use the included glue to attach the grip. The only issue I've had is that one of the ring terminals on the wiring harness was missing and had to be replaced. These grips are the best heated grips you can get for the money.
Heated grips were needed to extend riding season. they heat quickly, & have not needed to stay on 4/level long before moving to 3/2 in 40 deg. temp. I can wear reg gloves instead of big insulated ones. My 07' Honda Shadow grip for throttle was over large & had to adapt a piece of skate board tape to take up the gap before glueing R-side on. L-side was correct snugness. I used 2"x4" sbt W/rough side to plastic throttle. Krazy glue that comes w/kit was thinner than I expected & ran thru grip fast. Install directions are Very sparse.