Description: [High material]: This Motor Bicycle Chain Wheel is made of steel, sturdy and lightweight. high hardness, effectively protect sprocket from collision, strong impact resistance, no deformation. [Thicken design]: Use thick material, protect tooth plate from the damage of rock. [Design]: Small size, lightweight. Very easy to install, and smooth performance. [Multifunction]: It is used to avoid hitting the tooth disk when riding over obstacles and play a certain protective role. [Application]: When used as bicycle chain accessories, this pinion gear is suitable for all kinds of ordinary bicycle chains. Also, It can be used as motor parts and suitable for MY1016Z/1018 reducer motor. Specification: Item Type: Pinion Gear Material: Steel Applicable motor: MY1016Z/1018 reducer motor Size Chart: 9T: 4.1cm/1.61inch Total thickness: 9mm/0.35inch Tooth Thickness: 3mm/0.12inch 13T: 5.8cm/2.28inch Total thickness: 9mm/0.35inch Tooth Thickness: 3mm/0.12inch Package Includes: 1 Pinion Gear Note: Please allow slightly errors due to manual measurement and different monitors.