Item No NVK-5105 Description Novak's Mod 1 Steel Pinion Gear for 5mm Shaft, which are available in eight gear-tooth sizes, are recommended when converting 1/8-scale nitro off-road vehicles for brushless electric use and fit seamlessly with Mod 1 spur gears commonly found on 1/8-scale nitro vehicles. These hardened gears can be used in any application and with any motor that has a 5mm output shaft, includingNovak's HV High-Voltage Brushless Motors. All Novak gears include a set screw and have the gear size marked for easy identification.