A quick and easy way to hold the crankshaft while loosening and tightening harmonic balancer retaining bolt on popular Ford engines. Adapter securely fits the crankshaft to keep it from rotating when loosening the pulley bolt. Can use with 1/2" drive ratchet or breaker bar. Ideal for rotating the engine for timing related jobs. Designed to fit multiple Ford vehicles ranging from 1992 to 2016.