This tool helps you to know easily and quickly the wear of the chain. It is essential but simply to use.
A worn chain widely increases the consumption of the sprocket and of the engine sprocket.

This tool has 2 measurements:
- side 1: you can define when you should not use the chain during a race
- side 2: it determines when you MUST immediately change the chain because of too much wear

If the chain doesn't fit the tool it means that the wear is not too much