This is a Magpul Industries Tee Shirt, model MAG1121.
Magpul is a proud to be an American company. There's only one Standard Magpul recognizes" and Magpul has put it on this 100% cotton tee.
Features:
4.3 oz 100% combed ring-spun cotton
Crew neck with set-in sleeves
Comfortable, tag-less interior neck label
Shoulder to shoulder neck tape
Double-needle stitching on hems and sleeves for durability