Material: This product is stamped 304 stainless steel, thickened design, longer service life and higher security. Advanced anti-theft device: There is a spring-loaded lock button to prevent the chain from falling. This can help you improve anti-theft and make it more secure. It is recommended for wooden and metal doors. It is designed to secure the door and allow viewing and ventilation at a safe distance. Easy Installation: Each set of anti-theft chains is equipped with four screws for easy installation. The anti-theft door chain from is designed to improve the security of your home. This limits/limits the degree of opening of the front door, giving you enough clearance to see who is in your front door. It features an easy release mechanism that allows the front door to be fully opened. Because it is completely surface mount, only a few basic tools need to be installed. Specification: Name: Anti-Theft Door Chain Material: stainless steel Main Color: Silver Package content: 1 x door chain, 4 x screws Size: lock length -12.3 cm, chain length -19.6 cm Use: Suitable for doors in houses, offices or other places.