Not a perfect tool but I am able to change pilot and main jet without even loosening the carb boots on my bike. I have also removed entire float bowl without loosening the boots. Easy to carry with you and well worth the price.
I purchased this with the hope that it would allow me to easily change the pilot and main jet on my Keihin FCR carb without having to remove the carburetor. It does the trick for the main jet, but it's not possible to rotate the carb enough to gain visual access to the pilot. As a result, I have to spend almost as much time trying to locate it as it takes to loosen the subframe and completely remove the carb. I'm sure there are others with greater dexterity who would be more successful with it, but for me it has been kind of a mixed bag.