This .45 acp raw steel, mag well is a necessary item if you want to permanently run .45 acp grease gun mags in your Mac-10. A gun smith may be be necessary as the old mag well must be cut off by grinding down the welds and welding the new well in place. Once its permanently attached, either re parkerize the entire lower or spray it with some OD dark green paint and the grip back strap should cover it a bit as well. The best way to cover it is to order our Mac-10 molded wrap around grip. call if you have any questions.