New ProForm universal SBC/BBC harmonic balancer installer.   This installer uses a thrust bearing to aid in installing the balancer.  Includes a 7/16" adapter for SBC engines, and a 1/2" adapter for BBC engines.  Use a tool properly, and it will last a long time.  Some tips for a long life and to prevent breakage : Avoid bottoming out the adapter in the crank, only rotate the large nut while holding the shaft, avoid rotating the hold shaft (this causes the adapter to turn and bind, possibly snap), grease the threads on the installer to prevent thread binding.  If the balancer is not moving on smoothly or the nut is getting very hard to turn : something is wrong, don't force it, start again!