I have had mine for around 4 years now, I think I bought them the last year of the Grand in OH. I have had great luck with them but it needs to be a bright sunny day. If targets are getting into any shadows they seem to be to dark but on bright sunny days there is not a better lens. These where originally designed for the Navy and Coast Guard for searching for blaze orange objects (people) in the Ocean.
PS they have a newer lens color for the CMT then the version I purchased, they say the newer ones are better.