An excellent addition to an already excellent riflescope the Leupold Alumina Flip Back Lens Cover Kit - 50mm & Standard EP provides protection to your scope’s objective lens with triple O-ring seals and a strong magnet to keep the cover securely closed. These lens covers are made to fit onto Leupold scopes manufactured after 2004 with 50mm objective lenses. Made out of 6061-T6 aircraft aluminum, these lens covers are lightweight and durable.