【Strong Stainless Steel】Door security devices with chain are made of stainless steel. About the heavy-duty chain lock: body length 12.7 cm; chain length 17 cm; material thickness: 1.6 mm. H&Q steel has high hardness, is corrosion-resistant, rust-resistant, sturdy and durable, which further enhances its anti-burglary properties. Stainless steel is used in our chain locks, door chain locks, interior door chain locks, and chain locks. 【Anti-theft Design - Child and Pet Safety】Equipped with a spring-loaded anti-theft lock that increases security and provides reliable intrusion protection. Protect your family with extra locks, whether it's the front door or the interior door. Security locks for interior doors and chain locks for exterior doors can also be used for child safety or to help small pets safely enter and exit the house. 【Hand-Brushed Finish】HQ stainless steel with a hand-brushed finish, clean and beautiful, ensuring the chain lock is rust-resistant and has a long service life. Choose from additional lock options such as brushed nickel, matte black, red bronze, gold, and bronze for your doors, perfectly complementing modern home decor. 【Security Window or Ventilation】The heavy-duty chain lock is a door lock that provides a safe view and ventilation when the door is partially open, providing extra security for your home and office doors. For safety reasons, it cannot be unlocked from the outside. 【Hassle-Free Installation】Quick and easy installation - provides extra security for your home or office doors, right at your fingertips! All installation hardware is included in the package, so you can easily mount it.