Also the authentic NFL logo is on every jersey,
though i suppose these could be fabricated

it is a heavy mesh materiel, the numbers are sewn on, and the sleeves have elastic stretch on the end.

Also, the Reebok logo and name is on them (the official apparel supplier of the NFL).

The authentic nfl jerseys fit more and they are not loose. Their is a slit on the slide of the jersey at the bottom of the jersey the size and of course the sponsor i'm thinking predominantly reebok. Where the sleeves are it fits tighter around the sleeve and the jersey is a little heavier with the numbers and letters sewn on the back