Hey I just bought these lenses for my Flak Jackets and I'm having trouble with fitment. Item Number - 330799055481 I have standard and polarized lenses already that are XLJ's and they fit fine, you really have to apply a decent amount of force to snap them in place. However, these "standard shaped polarized lenses" don't snap in with nearly the same amount of force. I can click them in place with two fingers, whereas I need to use my palm for the XLJ's. How can I tell if they are authentic. Both my other polarized lenses have the OAKLEY engraved on the outside of the lens but these have it engraved on the inside... is this normal? Thanks in advance!