The door chain lock is made of high quality stainless steel, which is not easy to break, and the structure is not deformed. The surface is polished, brushed and rust resistant. Brilliant after long term use. Use the color matched door sensor to protect yourself as an accessory. Heavy duty bolt chain lock for interior doors, the chain has a combination of twist and tight welding, durable and tough to break. Easy to install, maintain and use. Easily lock or unlock from the inside. Thickened solid bolt lock cylinder, solid and wear-resistant. One of the important functions of this doorman safety chain limiter is to protect children. Install door guards high enough for your child to reach so they cannot safely open the door through the front door and prevent strangers from entering the house. < p>The latch allows the door to open a gap of about 3-5cm wide. Door controllers let you identify visitors when you can't let them in. You can also open the door slightly, but lock and ventilate the