The Topeak Chain Hook & Wear Indicator is a versatile tool designed for bicycle maintenance. It features an integrated chain hook that securely holds chain links during assembly, simplifying the process. Additionally, the built-in chain wear indicator allows for precise measurement of chain stretch, ensuring timely replacement and optimal drivetrain performance. This essential tool helps determine if your chain is worn out and needs to be replaced, preventing premature wear on other drivetrain components. It is constructed from durable hardened steel for longevity. Specifications: Tool Material: Hardened steel Size: 10.9 x 2.2 x 1.8 cm Weight: 9.6 g