I purchased this specifically to remove the rear upper arm on a 1999-2004 Jeep Grand Cherokee. There are 3 21mm bolts attaching the arm to the top of the rear axle. It's impossible to fit a traditional ratchet/socket there and it would take years for a regular wrench to remove the bolts. 21mm is quite large and the length of this wrench made it easier to loosen the bolts, especially since they come with Loctite from the factory. I also have a gear wrench set and this is my favorite budget ratchet.