This is the Aluminum Exhaust Header for the Traxxas Revo. FEATURES: Aluminum construction Silver in color Fluted on tuned pipe end for better silicone coupler connection Heatsink engine mounting flange INCLUDES: One Exhaust Header REQUIRES: Assembly to vehicle SPECS: Length: 59mm (2.32") Pipe diameters: Outside-13mm (.52") Inside -10mm (.40") Width between engine exhaust mount holes: 22mm (.866") COMMENTS: If needed, engine/header mounting screws, use TRAG5142.