Features1Good toughness, durability and long service life. 2Made of high quality metal material, good performance. 3Easy to use, stable performance, simple operation. 4It is a wonderful accessory for electric scooters. 5Professional manufacturing, stable performance and high reliability.SpecificationItem Type: Pinion GearMaterial: MetalColor: As Pictures ShownInner Diameter: Approx. 8mm / 0.3inNumber of Teeth: 11 ToothTooth Thickness: Approx. 2.5mm / 0.1inTooth Pitch: Approx. 6.35mm / 0.3inInstallation: D-type inner holeOuter Diameter: Approx. 25mm / 1inApplicable Chain: 25H chain (Half as thin as ordinary bicycle chains)Applicable Motor: Electric scooter and other high-speed motorsPackage List2 x Motor Gear