Updated design engineered and built to be light, accurate, and versatile \n 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, allowing 360 degree measurement \n Long and precisionextruded aluminum body is built to exacting tolerances and provides ample leverage for making adjustments \n Compatible with 16" to 29"+ wheels