Park Tool Derailleur Hanger Alignment Gauge Description:
The Park Tool DAG-3 Derailleur Hanger Alignment Gauge is designed and built to be light, accurate and versatile. The sliding indicator can measure derailleur hanger alignment against bicycle rims of any size, and rotates out of the way to clear seat stays, racks, and other obstacles. The long, precision-extruded aluminum body is built to tight tolerances and provides ample leverage for making adjustments.
