Fits for work with most popular domestic differentials such as GM 10, 12, 9.5, 10.5, 14-Bolt, Ford 7.5”, 8”, 8.8”, 9”, for Dana 30, 35, 44, 50, 60, 70, 80, and for Chrysler 10,12 bolt, 8.75, AMC 8-bolt, 8.875 in. The tool is capable of measuring many other differences where you might only need one hub.