The perfect tool for keeping your bike's drivetrain in top condition. This gauge, made of precision laser-cut steel, measures chain wear at the levels at which chain manufacturers typically recommend chain replacement (0.5% and 0.75%). The tool's three-point design isolates pin wear from roller wear, ensuring accurate results. Use the QR code to watch an instructional video. It works with all 6-13-speed chains, including SRAM flat-plate chains. As a general rule, 11-13-speed chains should be replaced at or before 0.5% wear, while 6-10-speed chains should be replaced at or before 0.75% wear. Monitoring chain wear is important because a worn chain can cause poor shifting and wear out other drivetrain components. Made of precision, laser-cut steel. Accurately measures 0.5% and 0.75% chain wear – the wear levels at which chain manufacturers most often recommend chain replacement. The three-point design of the tool isolates pin wear from roller wear. Includes QR code with video instructions for use Works on all 6-13 speed chains, including Sram flat chains. See chain manufacturer's replacement instructions. General rule for replacing a chain. 11-13 speed chains - replace before or at 0.5% wear 6-10 speed chains - replace before or at 0.75% wear