Strong & Durable: The door chain lock is made of high-quality steel, which is sturdy and durable. The surface is smooth and wear-resistant, suitable for long-term use Child Safety and Anti-Theft Design: The premium thickened lock is equipped with an anti-theft push lock, providing additional locking devices for the front door and interior rooms. You can use it to prevent infants from entering dangerous areas and prevent them from opening doors, providing additional safety protection for children Door Lock for Security: The chain locks are suitable for securing and locking various types of doors. They allow the door to be partially opened for observation and ventilation, preventing pets from opening the door or leaving gaps for pets to pass through, providing additional security Easy installation: The package includes the screws needed for installation. Simply measure the position of the door markings, drill holes, and install the screws. The installation process is convenient and simple Wide Application: The chain door guard with locks are suitable for many types of doors, such as bedroom doors, home front doors, apartment doors, rental room doors, dormitory doors, hotel doors, storage room doors, cabinet doors, etc