BBB chain gauge Chain Checker BTL-51
simple check the wear condition of the chain
suitable for all common bicycle chains
early replacement of the chain protects chainrings and sprockets
If the elongation of 0.75 = 75% is reached, the chain should be replaced.
Achieved the elongation 1.0 = 100%, then the chain must be replaced immediately! Since it is completely worn out!
Note: For correct use of the Chain Checkers sure to check the operating instructions of the manufacturer!