If you are directing your question to me, it is a 6 1/2 inch no-name I bought off of eBay. I bought it and a back plate with the proper threads for the Atlas and fitted them together. I decided that I wanted a truly stout chuck that had reversible jaws and this one met the criteria. It has one set of jaws that are each held in by two Allen screws. Instead of 2 sets of jaws, you remove the Allen screws and reverse the jaws, fitting them back into their slots. There is enough beef that I can tighten down and not worry about hurting the chuck. In addition, the jaws are almost 3 inches deep so when I need holding over a longer distance I have it. It looks too big, but it has worked out very well as far as I am concerned.Wanted to ask what size is your 3 jaw chuck ..it looks huge and where did you get it ???