Steel material and wire drawing treatment: The anti-theft chain door lock is made of stainless steel, which is sturdy and durable, not easy to fade and corrosion resistant. It can ensure your safety and have a long service life. The three-layer wire drawing treatment on the surface resists daily scratches and prevents collisions and kicks. Safety lock: There is a button with a spring-loaded anti-theft button. The chain can be opened by pushing the buckle, effectively preventing outside people from reaching the inner hook and falling off the chain. This design will drop your chain and protect the house more closely, making your house safer. Thick chain design: The 3mm thicker chain is durable, not easy to break and will not break not easily when pulled hard. It can be used for a long time. Easy to install: The set includes a door chain lock and four screws that you can fix behind the door. Chains can be used on wooden or metal doors on all door types and can be placed above or next to the door frame. (The greater the distance between the buckle seat and the base, the smaller the opening angle) Theft protection: The security door chain provides additional protection based on locks and door bolts that can effectively prevent the intrusion of thieves and strangers, which is very suitable for people living alone. It can also prevent unauthorized children from leaving the house, providing additional protection for children's safety.