Features: The unique positive and negative tooth structure effectively improves pedals efficiency and reduces unnecessary energy loss. High strengths aluminum alloys component is selected, which is both light weight and wear-resistant, suitable for long-terms use. Circulars, to accommodate the habits and needs of different cyclists. Enhances the contact efficiency between the chain and the disc, promoting a smooth cycling experiences. Ensuring perfections in every detail and provide excellent performances. Specifications: Color:Four Elections Dimension:40mm/1.57in 50mm/1.97in 60mm/2.36in 65mm/2.56in Component:aluminum alloys Package Includes: 1pc Narrow wide chainring note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you will not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual color.