STS-081 vs SIGTAC Mini (Amazon)

[ambis]

Hello,

Does someone know the difference between this:

http://www.amazon.com/SigTac-Mini-Red-Dot-Sight/dp/B001FT4S9E/ref=sr_1_8?s=sporting-goods&ie=UTF8&qid=1387685661&sr=1-8

and this:

http://www.sigsauer.com/SigStore/sts-081-mini-red-dot-sight-495.aspx

Besides 12 vs 14 position? Is the Amazon optic made by sig sauer, or is it a knock off?

[bridgeport]

Judging from the Amazon pic, the difference appears to be the length of the rail, The STS-081 has a longer rail with 3 attachment screws, the one on Amazon appears to have only one screw. I have an STS-081 on my Sig 556R ( comes with the rifle). So far it works well and I am happy with it.