Just got an email and placed an order for windowed Gen 2 Pmags and they have windowed Gen 3 as well. Get them while they're hot.
PMAG 30 M2 MOE Window, 5.56x45 - Magazines - AR15.COM Online Store
PMAG 30 M2 MOE Window, 5.56x45 - Magazines - AR15.COM Online Store