1. The helical motor gear is made of 45# steel, more stable, anti-wear, strong and durable, and durable in use.2. Material: 45# Steel, Finish: Black Oxide, Teeth: 16T, Tooth Depth: 2.3mm / 0.09inch, Gear Step Diameter: 20mm / 0.79inch, Gear Step Height: 8mm / 0.31inch, Outer Diameter: 22.63mm / 0.89inch, Aperture: 12mm / 0.47inch, Effective Tooth Length: 12mm / 0.47inch, Total Thickness: 20mm / 0.79inch, Module: 1 Mod, Pressure Angle: 20°3. The helical pinion gear aperture is 12mm and the module is 1, please check the size before purchasing.4. The gear has a black oxide finish for longer-lasting performance.5. Good hardened helical pinion gear replacement for your device.6. The gears are quenched at high frequency and can withstand extremely high strength.