Optigard released a video showing how to install the cover.... "The OpticGard Scope cover for the Holosun SCS MOS offers protection against stray bullet casings and scratches. The intelligent cut allows the cover to fit most rear and suppressor sights. It also includes a detachable training lens which will allow you to use the red dot even in the sun or bright areas. Our scope covers are made from a material made from TPU (Thermoplastic Polyurethane) offering protection from abrasion. In addition, the fast and simple installation allows easy access to the buttons without removing the cover. Finally, the interlocking pins secures the cover so it won't fall off even with heavy recoil from handgun slides."