For the benefit of people searching in the future, I would like to point out that the company has a
counterfeit notice on their website.
The main points seem to be
1/The counterfeits are cheap red dots disgusied as holographic sights. The image distorts near the edge of the sight window wheras a real sight doesn't distort.
2/The front and rear glass of the counterfeits are curved and reflect light wheras the real are flat and non reflective.
3/The real sight has a slightly curved "optical component" inside the top edge of the sight window.
4/Real Eotechs only ever appear red. The night vision mode is so dim it cant be seen with the naked eye.
5/Real Eotechs have a label on the bottom of the sight.
Anyway, better follow the link and download the PDF at the bottom of the page. Of course buying new from a reputable dealer is one way to guarantee that you are getting the real thing.
By the way, the owners manual states in BOLD letters "CAUTION- There is a 12V battery that is approximately the same size as the Type N 1.5V battery. DO NOT USE 12 V battery. They will severely damage the sight."