Excellent...nearly perfect!
This is a sturdy and well constructed magazine. I like that the back of the cartridge lifter is beveled. This allows you to close the bolt on an empty mag and feed single shot (chuckability) if you desire. A surprising number of other brands of AICS mags wont allow the bolt to close on an empty mag. If I have one complaint it is that the mag has VERY close tolerances. I paired it with an American Precision Arms trigger guard/floor plate, and getting it in and out was a chore until I filed some additional clearance into the mag well. It wasn't hard - it's certainly better than too sloppy. Just buy it...it's great product!