I first bought the Husaberg guard. Over priced and didn't cover enough of the pipe. I then bought the P3. Mine seems to be shaped slightly wrong - it doesn't follow the pipe perfectly. But you can only tell if you look close. It works great.
I think E-Line sells a similar one for a similar price, and Flatland Racing makes an aluminum one for about half that price. I haven't used either, but they look like they would do the job.