Don't risk altering the crankshaft end play by pounding the harmonic balancer into place! This tool supplies the steady force needed to correctly mount the Balancer on the crankshafoot The 8 adaptors (7/16in.x20in., 1/2in.x20in., 9/16in.x18in., 5/8in.x18, 3/4in.x16, 12mmx1.50, 14mmx1.50, 16mmx2.0) will fit both domestic and foreign cars. Requires 1 1/4in. capacity wrench. Replacement adapters available (7/16in. x 20). Limited 1 year warranty.