Detection tool: this tool can quickly check the stretch and wear of the chain to determine the quality of the chain. Accurate and durable, it can solve most bicycle problems. Sturdy and durable: compatible with most bicycle chains made of 304 stainless steel, sturdy and durable, rust-proof, not easy to damage, normal and long service life. Easy to use: the chain hook can attach the chain link during the assembly process. This is convenient for your recognition, even if you are alone, and can make your work more efficient. Convenient to wear: the chain wear detection tool is small, lightweight and easy to carry. When you ride outside mountain bike, you can put it in your bag at any time for easy access. Good gift: the bike chain wear indicator is a useful tool for bike maintenance, which can prevent worn chains from breaking or damaging other parts. It is an ideal gift choice for cyclists.