Thread the gauge directly into the derailleur hanger. Align the derailleur hanger by applying pressure to the tool arm.
TOOPRE Professional Bicycle Derailleur Hanger Bike Tail Hook Alignment Tools New
TOOPRE Professional New Bicycle Derailleur Hanger Bike Tail Hook Alignment Tools
Bicycle Derailleur Hanger Alignment Corrector Professional Detachable Accessory
TOOPRE Bicycle Derailleur Hanger Alignment Gauge Straightening Tool Cycle Repair
New Bicycle Derailleur Hanger Alignment Corrector Detachable Repair Accessory