Stern defense m&p 9mm maxgwell adapter - Stern Defense MAG-ADMP9&40/P320 AR-15 M&P 9mm/.40 Magazine Conversion Adapter

I was building an ar-9 when the choice of how I was going to feed it came up.I chose a Stern Defense magwell adapter for M&P pistol mags(I own a 2.0 and have many xtra capacity mags already).Assembly took 5minutes(literally) and it cycled and ran perfectly.Ets plastic,m&p oem and pro mags ALL RUN PERFECTLY with no issues.This adapter cost a little more than the sylvan and endo mags but it perfectly suits my needs.Sterns customer service was top notch and I was actually very impressed at their attention to the small details and making sure I was totally satisfied with my purchase.