The overall quality for this is not quite up to Oakley specs.  The lenses feel a little bit thinner, they don't come out and snap into the Oakley frames quite as easy either.  This seems mainly due to the edges of the lens being less finished. Oakleys are almost rounded on the edge, these are more squared.  For optical quality, I can't tell the difference.  Based on how much cheaper these are than Oakley replacement lenses, I can easily forgive the slight drop in quality and rate them 5-stars!