Traxxas 5487 T-Maxx Resonator Double Chamber Tuned Pipe Tuned aluminum resonator pipe for Maxx trucks with TRX racing engines Precision-engineered on the dyno to increase power output Provides an average Peak Torque increase of 16% resulting in brutal bottom end punch A 10% increase in total power across the whole range provides smooth power delivery, perfect for the back yard or the race track. Resonator pipes are fully polished to a beautiful mirror-chrome finish with a laser etched logo Use Traxxas stock and hop-up replacement parts to get the most out of you Traxxas RTR vehicles This product is made from high quality materials and designed for lasting performance This is for use on RC vehicles, consult your user's manual for exact parts listings