Worked as advertised. good quality. - Stern Defense MAG-AD9 AR-15 Glock 9mm/.40 Magazine Conversion Adapter

I had previously wasted time and money buying and testing another mfg's mag adapter which did not work. A major fail. This mag well adapter approach and design is flawless. Installation took only a minute. Dropped in my foreign made g-17 9mm mag, headed to the range, and pulled trigger. It was flawless after 50 rounds. (I did simulate at home by cycling the whole mag and oiling the interfaces. Made an adjustment by pulling the adapter out to the max travel and tightened the set screw.)