• Set of 2 central hub lockring discs for bicycle • Made of stable aluminum material, high strength and lightweight • Rust-resistant, durable, and not easily deformed • Long service life and high performance • Easy to install and remove, suitable for barrel axles • Inner diameter of lock cap: approximately 21 mm; outer diameter: approximately 35 mm • Compatible with center lock adapter, mounts on intermediate lock hubs • Brake disc rotor lockring suitable for mountain and road bikes • Professional processing that smooths the exterior and prevents wear • Simple design and black color that protects and decorates the bike • Can be installed and replaced on the front or rear • Ideal for bike enthusiasts who do DIY