I have one on my 400, but I don't think I have any pictures of it.
The one I have is the Trail Torquer. The idea behind it is to boost low and mid power, but some top speed is lost. On paper, it took my 62 and 1/2 horsepower engine to 65 horses, and changed the power curve. I'm not sure if it really did add hp, but it sure helped wake up the low and mid range.
Dave
Sheboygan WI
Rudely Awakened From The American Dream