A little bout of sticker shock is expected when pricing replacement cassettes. That's because they require extensive engineering and are expensive to manufacture. Because of this, Pedro's Chain Checker Plus serves as an essential tool if you plan on preventing premature wear to the cassette. With the Chain Checker Plus, you're able to quickly determine if a chain is within proper specification. And if it's reached the limit, it's time to replace before compounding damage ruins the cassette. On top of keeping an eye on excessive chain length, Pedro's added other useful features. These include a chainring nut wrench and a chain hook tool, which assist with the chain reconnection process. Pedro's Chain Checker Plus is constructed from tool quality steel and comes with a lifetime warranty.