Its a bearing and race installer/remover. I have another set, but it starts out way smaller and the largest one in that set ends just a size or two smaller than where the one pictured starts out. I'll probably never use it for anything other than the transmission rebuild but I feel better having a tool that is for that purpose. If push comes to shove I can always sell it when the work is done, but I service a lot of vehicles so it may come in handy again.