1、Lightweight and Durable Carbon Steel Material: This is a small engine sprocket made of premium carbon steel material, which is sturdy and durable. 2、Easy to Install: The sprockets are small in size and light in weight. The installation is very easy and the performance is stable. It can bring a good experience. 3、Improve Efficiency and Performance: You can replace old damaged chain sprockets parts with new chain sprocket to improve efficiency and performance. 4、Applicable Scenario: This 428 12T 20mm front sprocket and 10 tooth 12x17mm H hole chain sprocket set is suitable for ordinary engine sprocket chains. 5、Warm Tip: Please verify model number and size prior to ordering to ensure this is the correct part,428 represents the chain model, 12T is the number of gears, and the last is the size of the mounting hole, you can buy it on demand.