1. Good materials: This product is made of good materials, able to withstand relatively high pressure and not easily damaged. 2. Good safety: Choke cables add protection for household safety, health, and the safety of infants/children. 3. Easy installation: It is made of a 19 - centimeter-long steel wire, equipped with self-drilling screws and a wrench. Installation can be completed with just a screwdriver or an electric drill. 4. Wide application: It is suitable for PVC, aluminum, wooden, and composite doors and windows. It can be used for sliding windows (up - and - down), casement windows, and sliding windows; balcony doors, guest room doors, etc. 5. Locking and unlocking: The special limit design can limit the window to open 19 centimeters and let in fresh air. After pulling out one end of the cable with a wrench, the window can be fully opened. When the cable is in place, the opening distance of the window is restricted. The cable can be removed from one end using a wrench to fully open the window. 6. Stylish appearance: It has a novel shape, smooth lines, can be bent freely, and the cable spacing can reach 18.5 centimeters. 7. Special lock cylinder: The special lock cylinder design improves the security of the door lock. 8. Package contents: It includes 4 products.