This prescription adapter is exclusive to the Parole and Vigilante frames. All you have to do is take the adapter to an optical professional for a prescription lens. Once you have the lens, insert and snap it in behind the sunglass frame. The adapter snaps in easily without altering the nosepiece. You'll then be able to enjoy true vision and protection without any discomfort. - Large Size fits Vigilante - G537. Small Size fits Parole - - Code: G538
