BEWARE: purchased a set of lasers they were not functioning correctly. had several physicists' workdays installing the laser they are supposed to be independent, but they are not and impossible to fine tune as they jump centimeters. we tried to return them but because some of the paint on the mounting brackets was removed, they would not take them back and even if it was still in the boxed unopened the charge a 30% restock fee! they cost 6K that is $1800 this is a small company and a niche product not sure how it cost that much to restock? I spoke with what I believe are the only two that have the authority to authorize a return (Ron, Fred) less then helpful!!!! Please don't make the same mistake as we did!!!!