19 mm Harmonic Balancer Socket & 50mm Crankshaft Crank Pulley Wrench Holder for Honda and Acura Engines. 【19 MM Harmonic Balancer Socket 】--The hex socket is used with an impact wrench to loosen the crankshaft bolt It can be used on Honda engines that use a 19mm hex pulley damper bolt or other 19mm applications.