Features: Make of metal Alloy with high strength, light weight, rust resistance and durability, none easy to deform. Can be used for shaft, suitable for mountain bike, very easy to install and remove with the quickly release whelset type. Adopting precisely machining technology, easy installation, can effectively fix the disc, prevent loosening, and improve riding safety. The unique cover locking rings design makes the installation process simple and fast, taking only a few seconds to complete. The surfaces has undergone special treatments to enhances its wear resistance and extend its service life. Specifications: Component:metal Alloy Color: Black/Gold/Colorful Diameter: about 44mm/1.73inch Package Includes: 1pc Road Bike Center Lock Cover rings note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.