The TOOPRE TOL-2.5 Derailleur Hanger Alignment Gauge is a professional bicycle repair tool designed to check and correct bent rear derailleur hangers. Made from durable aluminum alloy with a stainless steel measuring rod, it helps improve shifting accuracy and solve common drivetrain issues caused by hanger misalignment. Featuring a 360° rotating design, adjustable sliding bracket, precision threads, and boxed packaging, it is suitable for MTB, road, gravel, folding bikes, and most bicycles with replaceable derailleur hangers.