Features: Material: Made of quality aluminum alloy material with high strength, rust resistance and durability, no easily to deforms. CNCMachining: CNCmachining treatments can make the outside smooth, and can also prevent wear and tear. Size: The inner diameter of locking cap is about 30.6mm/1.20inch, outer diameter is about 44.7mm/1.75inch. Applicable Types: It can be used for barrels shafts, compatible for mountain bike, easily to install and remove. Uses: Using with centerlock adapter, mount on the middle lock hubs, 9/12/15/20mm axes are all available, so it can install 6 bolts disc. Specifications: Material: Aluminum Alloy+Stainless Steel Color: As The Picture Shows Package Weight: approx.12g Style Options: 8 Style are Available as Shown in the Picture. Size: As The Picture Shows Note: Please allow 1-3mm error due to manual measurement. Please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks! Package includes: 1Pc Lock Rings