Description: 【Multifunctional Tool】: This Bike Chain Checker is a versatile tool designed for chain wear measurement, length measurement, screw diameter measurement, and chain repair with hook function. It's an essential chain tool for every cyclist. 【Chain Wear Indicator】: The Bicycle Chain Wear Indicator Tool features wear measuring hook that fits into the chain link. If it doesn't fit at all, your chain is in great condition. If it fits at 0.75, your chain has worn but can still be used for some time. If it fits at 1.0, your chain is severely worn and should be replaced immediately. 【Convenient Chain Hook Function】: The back of the Chains Measurement Ruler has two hooks to hold the chain in place during repairs or cutting operations, making it easier to work without getting your hands dirty or having the chain spring up. 【Material】: Made from stainless steel, this Bicycle Chain Checker is sturdy and resistant to rust and corrosion ensuring long term use. 【Portable】: The Bicycle Chain Wear Indicator Tool Chain Checker dimensions are 42*125mm, making it lightweight and portable enough to carry around on rides if needed. Specification: Material: Stainless Steel Size Chart: 4.2cmx12.5cm/1.65inchx4.92inch Package Includes: 1 Bike Chain Checker(5 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.