Tuned pipe Resonator R.O.A.R. legal (single-chamber enhances low to mid-rpm power) (for Jato N. Rustler N. 4-Tec with TRX Racing Engines)Traxxas Resonator aluminum tuned pipes are precision engineered on the dyno to increase the power output of TRX Racing Engines. The Traxxas engineering team knows TRX Racing Engines better than anyone, so Resonator pipes deliver proven results that drivers can see, hear, and feel every time they pull the trigger. Resonator pipes feature R. O. A. R. legal stingers and come in single and dual chamber versions. It