This is the Exhaust Coupling for the HPI Firestorm, HPIC0510. FEATURES: Constructed of composite plastic YOU WILL RECEIVE: Exhaust Coupling with two zip ties REQUIREMENTS: Installing between tuned pipe and header SPECIFICATIONS: Length: 1.2" (31mm) Inner Diameter: 0.51" (13mm) jxs 03/14/07 ir/jxs &