With 16 review ratings and a 3 star average I would guess they are probably aftermarket (old DPMS stock?). Or perhaps the lower review is because they are used and don't mention it. Either way it is a good deal considering they can't be found anywhere I just wish they didn't come at a time I was so broke. I could definitely use a few of these, if they are there in a few days I will have to order a couple of them. There should be some reviews by then letting us know if they are USGI or DPMS ones.
Honestly, I don't care much either way since I like to replace the A1 sight with the A2 aperture anyways. The DPMS ones have always worked fine for me, just add a cheap A2 aperture. Any coupon codes for Sarco? Shipping looks reasonable - $6 for 2 and it goes up to $8 for 3. I hate when a company charges $15 to ship something small.