so im goin to b putting these on my ar as backup to my new eotech. i have seen a set of these on ebay for 25$. now i know they make some of these for airsoft. but the seller does not designate them for airsoft, and the pics on ebay show them on a real AR style rifle, couple pics actually. are these knock ofss or what???? does anyone know more about these that can let me know if there knockoffs?? thanks everyone.