[Feature] Modulus: 0.5M, number of teeth: 72T, aperture: 6mm, [Feature] Description: This gear is suitable for non-load use within 8 hours, with good precision and high concentricity [Feature] Made of 45# steel, strong and durable [Feature] It is mostly used for personal DIY, small machinery, micro generators, etc. [Feature] If you have any question about the product, feel free to contact the CNBTR Service and we will try our best to give you a satisfactory answer.