Good for midlevel pcc when you have 320 mags - Stern Defense MAG-ADMP9&40/P320 AR-15 M&P 9mm/.40 Magazine Conversion Adapter

I don't have Glock mags but i do have 320 mags and i wanted to try doing some PCC stuff. So far fit and function is good and the system works well. Only real "complaint" is that it does take some adjusting to operate smoothly and if your system is already heavy this won't make it any lighter. If you can use a dedicated lower like the epc it would be better but if you have a spare standard lower then this is great.