Product features The perfect tool to keep your bike's drivetrain in top condition. Made from precision, laser-cut steel, this indicator precisely measures chain wear at levels where chain manufacturers commonly suggest replacing the chain (0.5% and 0.75%). The three-point tool design isolates pin wear from roller wear, ensuring accurate results. Use the QR code to watch the instruction video. It works on all 6-13 speed chains, including SRAM flat top chains. As a general rule, 11-13 speed chains should be replaced before or at 0.5% wear, while 6-10 speed chains should be replaced before or at 0.75% wear. Staying on top of chain wear is important as a worn chain can cause poor shifting and wear out other drivetrain components. Made from precision, laser cut steel. Precisely measures 0.5% and 0.75% chain wear – wear levels where chain manufacturers most commonly suggest replacing the chain. Three point tool design isolates pin wear from roller wear Features QR code with video usage instructions Works on all 6 -13 speed chains, including Sram flat top chains. Refer to chain manufacturer replacement instructions. General rule for replacing the chain. 11 – 13 speed chains – replace before or at 0.5% wear 6 – 10 speed chains – replace at before or at 0.75% wear