The Park Tool CC-3.2 Chain Wear Indicator is a great way to monitor how worn your chain is. A worn chain shifts poorly and will wear the sprockets quickly so it's important you regularly check it to keep your machine performing smoothly. This Park Toolbike tool boasts a Go/No Go guage which has been designed to give accurate readings whenever a chain reached 0.5% to 0.75% wear. This is the point when most manufacturers would suggest a replacement to prevent the other drive train components from wearing ot fast. This handy little Park tool features a longer design which means you can measure a greater length of chain to give the best possible accuracy. Made from precision, laser cut steel and compatible with 10 speed chains this is a great addition to your workshop tools ... More info