The Lisle 21mm and 22mm Harmonic Balancer Sockets, Nos. 77100 and 77110, are heavy duty impact sockets designed with more than three times the standard socket mass to direct more energy to removing the bolt, according to the company. The 21mm Harmonic Balancer Socket can be used on Chevy, Chrysler, Dodge, Ford, GM, Jeep and Mazda engines that use a 21mm hex pulley damper bolt or other 21mm applications. The 22mm Harmonic Balancer Socket can be used on BMW, Dodge, Ford, Jeep, Kia, Lexus and Toyota engines that use a 22mm hex pulley damper bolt or other 22mm applications. Both sockets can be used with a 1/2” drive impact.