This is the Robinson Racing Forward Only Wide Ratio Gear Kit for the Traxxas T-Maxx 3.3 and Revo 3.3. FEATURES: Installs in gearbox to allow forward only operation INCLUDES: One 13T and 18T wide ratio top shaft gears Forward only gear kit 38T Second gear 43T First gear REQUIRES: Installing gears in gearbox Transmission Output Shaft (TRAC5369) COMMENTS: Contact the manufacturer for information on the gear ratio tlw 7/10/07 ir/jxs cnh 11/27/09