Material: This door viewer is made of durable zinc alloy for long-lasting use and wear resistance. Easy installation: Compatible with doors 40-65 mm thick and a 16 mm tube diameter. It installs easily without professional help. Theft-resistant design: Anti-lift and anti-twist features enhance security for homes and hotels. Function: Lets you clearly view the full height of a person outside from head to toe. When the cover is in place, outsiders cannot see into your home through the peephole. Use scenarios: - Residential front door: verify visitors at a glance before opening, with the option to shield the view when privacy is desired. - Hotel guest room: quickly check who is at the door while maintaining guest privacy when needed. - Rental properties or small offices: monitor entry points to deter unauthorized access and improve security. This description highlights material, compatibility, security features, viewing capability, and practical applications in a concise, readable format.