ANTI RUST TREATMENT: RC pinion gear set with rust proof treatment is an ideal replacement for old or damaged original parts for 1/8 RC model car motor 5mm shaft motor. STABLE WORKING: RC car pinion motor gear works smoothly and has good machinability, roughness and low noise compared with other pinion gears, making them roll smoothly. MOLYBDENUM ALLOY STEEL: RC motor gear is made of high precise molybdenum alloy steel, and the gear is heat treated process for high wear resistance, corrosion resistance and good performance. FOUR DIFFERENT TOOTH NUMBERS: Pinion motor gear provides four kinds of pinion gears with different numbers of teeth, giving you more choices in gear ratios and making your RC car perform better. SERVICE GUARANTEE: If you are not satisfied with the RC Car Gear Sets we received, you can contact us by email at any time, we will reply and solve your problem in time, and strive to provide better service. Specification: Item Type: RC Car Gear Sets Material: Molybdenum Alloy Steel Color: Black Number Of Teeth: 12T 13T 14T 15T Gear Pitch: 25DP 1.0M Center Bore Diameter: 5.0mm/0.20in 12T Size: Diameter 14x13mm / 0.55x0.51in 13T Size: Diameter 15x13mm / 0.59x0.51in 14T Size: Diameter 16x13mm / 0.63x0.51in 15T Size: Diameter 17x13mm / 0.67x0.51in Applicable For 1/8 RC Model Car Motor 5mm/0.20in Shaft Package List: 4 x Motor Gear 4 x Grub Screw Note: Please allow some error due to manual measurement.