High-quality materials; The porthole is made of alloy material, which is durable and can increase your privacy. After coverage, visitors outside cannot see your home through the public, providing the highest level of privacy for your protection and security. Wide field of view; A 220 degree perspective provides security to identify visitors from behind closed doors. You can easily view the entire surrounding area from the top of the head to the feet of people standing outside. Protection; These security door accessories will protect your home from burglary, invasions and family invasions, and provide security for you and your family. Easy Installation; The back cover of the door viewer with anti-indiscretion belt can be replaced within 5 minutes without tools after installation and disassembly. Scope of application; Alloy peephole camera applicable to door thickness: 35mm-55mm, applicable to wooden doors, fiberglass doors or metal doors.