http://www.military.com/daily-news/...tles-lawsuit-over-defective-rifle-sights.html I learned about this through Larry Vickers and I am posting this for those of you with one of their products. EoTech is a major supplier of weapon optics for the US Military and civilian market. They were sued by the Feds for knowingly concealing a very serious defect in their product. As a result of that lawsuit, they are buying back products, yes, even from us civilians, on a case by case basis. The problem is thermal drift. For example, if you zero the optic at 60F and the weapon is subjected to temps below 35 or above 100, there can be change in the point of impact this is something the lawsuit proved they knew about and concealed the defect from the military and worked to cover it up. They got caught. If you have one of their optics and want to send it back, go to their website and fill out a return authorization form online. If you have the original receipt that helps a lot you give them some info on your optic like SN and date of purchase and how much you are claiming for a refund. In a day or so, you get an email saying your request is approved and to send it back to them and they will pay you back the full purchase price plus $15 shipping. They were very fast and courteous to me. My 512 is on its way back and when I get my money back I will be buying an Aimpoint to replace it I could not live with the old optic knowing it could fail and right when I needed it most. It was on my SHTF rifle.