TRP Lock Ring For Centerlock Rotor Lock It Up If you're using a centerlock rotor on your wheels, you'll need a lock ring to keep the rotor in place while you're riding. The TRP Lock Ring for Centerlock Rotor is designed to work with 15mm axles. It is made of lightweight and durable aluminum alloy and is perfect for any rotor. Features Designed for wheels that use a 15mm axle Works with any rotor Material: aluminum alloy | Trp | Lock Ring For Centerlock Rotor 15Mm Axle