Shomer-Tec Reverse Peephole Viewer Developed to assist law enforcement officers assess potential threats and view real-time activity behind a door when the door has a peephole Provides a clear, discreet view into the room through a doors peephole Effective on all major brands of standard door peepholes used on apartment, hotel, and residential doors Newly-updated and improved version of one of our most popular products provides a clear, discreet view into the room through a doors peephole Length: 2.8 ; Weight: 2.2 oz. Field-of-view: 15 degrees