Before anyone else runs out and buys an Arredondo (P-140K) Para .45 extended base pad...DON'T, they do not fit either the stock 97B magazine or the Mec-Gar 97B magazine. You slide it on, it pops right off. It is too narrow front to back and too wide side to side to stay on. The retention clip that comes with it does not fit into the 97B magazine so even if it would fit there is no way to keep it on the magazine.