Unior 1644/2 Manual Chain Wear Indicator Description: The 1644/2 Manual Chain Wear Indicator is designed for anyone interested in quickly checking the health of their chain. This indicator is constructed out of precision laser cut steel for durability and long term accuracy. When it is time to use the tool, a high contrast black oxide finish makes it easier on the eyes to see the numbers on the tool and quickly assess if the chain is okay or if it needs to be replaced. Features: Precision laser cut for repeatable and accurate measurements Simple drop in design with high contrast black oxide finish make it easy to get a fast and accurate measurement Compatible with up to 12 speed chains