Check the listing for details. Off-road Enhancement Kit for Evolve GT, GTX, GTR. Condition: New. Listed at 95.00 USD. The Off-road Enhancement Kit includes our 13 Tooth Driver Kit and Heat Sink Kit. This kit improves performance off-road by reducing the gear ratio, providing 15% more torque and increasing range by reducing the load on the motors. The heat sinks increase efficiency and range by keeping the motors cooler in off-road conditions.Heat Sink Kit:Increases surface area by 40% to help the motors run cooler in hot weather and the higher loads of off-road riding.Increases run time by reducing electrical resistance brought on by elevated temperatures.Extends motor longevity.Simple installation.Tools required:Large flat blade screwdriverIf installing on older generation Evolve motors with external shaft collar, it will be require that one of the motors is removed.13 Tooth Driver Kit:Increases torque by 15% by reducing the number of teeth from the stock 15 tooth to 13 tooth. Good compromise of torque and top speed with 7" tires. Made from steel like the stock gear. Includes new belts and set screws.Tools required:1.5mm and 1/8" allen wrenchesLarge flat blade screwdriverSmall torch (highly recommended to ease removal of stock gear)