I bought this along with the black ISO grips and bar weights. It went on fine and the screws I needed to install them properly were included with the bar weights, but if you don't have bar weights, you get the screws you need with the throttle boss. It is REALLY big on the throttle. I would say that it is about 1/2 the length of the throttle. It adjusts with 4 large "slots" cut around the mounting screws allowing it a wide but limited range of motion. Depending on how you install your grips, I can see having a little difficulty finding a good "sweet spot" for maximum comfort. And I found that where I have it installed for comfort on the highway, it gets in my way a little bit with rolling off the throttle and grabbing the brake lever. That was the only reason for the 4 stars. I might recommend the smaller version for the same result and it would be a lot less obtrusive during braking. I would even go as far as to say that if you don't have arthritis, you would probably like the smaller version better. If I decide to try it, I will review again. As far as doing what it's supposed to do, it allows me to release my death grip on the throttle and rest my palm on the boss to keep the throttle open when using the cruise control is inconvenient.