Don't let your worn-out chain ruin the rest of your drivetrain. This handy tool is quick and easy to use, and can save you some serious headaches. This "go/no-go" chain gauge is designed to let you know when your chain reaches .5% and .75% wear, which is when most chain manufacturers recommend replacement. This tool is compatible with most 9 speed through 12 speed chains. For 9 and 10-speed chains, use the 0.75% side and replace when the gauge fits flat into the chain. For 11 and 12-speed chains, use the 0.75% side and replace when the gauge fits flat into the chain. 

Features:

• Indicates both 0.5% and 0.75% chain wear
• Compatible with most chains from 5 to 12 speed
• Updated design is longer for more accuracy
• Permanent measurement markings won't rub off with wear
• Not compatible with SRAM 12-speed AXS road chains (Flattop)