This is a Dynamite Polished Aluminum In-Line Tuned Exhaust System for the Traxxas T-Maxx 2.5, 2.5 Classic, Stadium Maxx, and Sport Maxx.  If you like power, performance, and the awesome look of polished aluminum, YOU NEED THIS PIPE.  Not only does in increase the top speed and acceleration, but it makes your truck look AWESOME.