Material: Made of high-quality material, can withstand higher pressure, not easy to damage. Excellent Safety: High-quality choke cable for enhanced safety, health, and home/child safety. Easy Installation: Made of steel wire measuring 19cm long, comes with self-tapping screws and wrenches, only a screwdriver or drill to install. Versatile Use: Ideal for PVC, aluminum, wood, composite doors and windows. Use on double-hung, casement, and sliding windows; balcony doors, guest room doors, etc. Locked and Unlocked: Special limiting design provides 19cm of restriction and fresh air, and the window can be fully opened when the cable is pulled out from one end with the wrench. When the cable is in place, the distance the window can open is limited. With the wrench, you can remove the cable from one end and open the window completely. New shape, smooth line, can be bent at will, cable distance up to 18.5cm. Unique lock core, significantly increased door lock security. Package Includes: 4 Pack