Need information on the White Brothers rev box

I've heard everyone one say they have a white brothers rev box and i'm not real sure what it does.Can someone give me an idea of what all it does.

[nakomis0]

It gives you about an extra 1000 rpm. Which doesn't help much on a stock bike, you feel it much more on a high modded bike. Its also a pain in the arse to start in the winter with a rev box. I just switch back to the stock one for winter riding.

[Tlongs400]

everybody i know all went back to the stocker!!

Don't waste your money,,spend the money on a cam or piston,,I used one and sold it 8 months later and went back to my stocker..plus on a dyno,,the WB CDI produced NO power gains..