Purchase standard: Measure the distance between the two holes in the center of the two holes, the number of good teeth teeth, the corresponding model to buy shield (cover on the number of teeth on the number of teeth).Common tooth number of teeth: 42 teeth 4 holes center size 10CM 42 teeth 4 holes center size 10.5CM 44 teeth 4 holes center size 10.5CM 44 teeth 4 holes center size 11CM 48 teeth 4 holes center size 12CM 48 teeth 5 holes center size 10CM 48 teeth 5 holes center size 9.5CM 50 teeth 5 holes center size 10.5CM Our products are made with the highest quality materials and are designed to provide you with the best possible user experience. We strive to ship out all orders within three days of purchase, and the estimated delivery time is 7to14 days. When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''t hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it