Those are AC-Unity Mags They are good mags but may require fitting depending on if you have a factory gun or kit build. They fit most of my guns, but a few builds I have they seem to need the tab filed to fit. This is not a problem for me but may be for some. They are well constructed and would last a long time.
I bought some of the 40rders they are good quality for a polymer mag but didn't fit my Morrissey receiver RPK, Arsenal 107UR, and WASR 10/63, they did fit in my NGS receiver perfectly but everything fits into that thing. Just my experience, I've heard good things about them too and it seems like they'll fit with some minor shaving/modifying. Yes they do have metal lugs.