JINYU Material Made of high-quality material, it can withstand higher pressure and is not easy to damage. Superior Safety High quality choke cables for added safety, home health and safety, and baby/child safety. EASY TO INSTALL Made of 19cm long wire with self-drilling screws and wrench, just a screwdriver or drill can be installed. Ideal for large PVC, aluminum, wood, composite doors and windows. For double-hung windows, casement windows and sliding windows; balcony doors, guest room doors, etc. Locking and unlocking Special limit design, providing 19cm restriction and fresh air, the window can be fully opened by unplugging one end of the cablewith the key. When the cable is in place, there is a limit to how far the window can be opened. Using the key, you can remove the cable from one end and fully open the window. New shape, smooth lines, can be bent at will, and the cable distance can reach 18.5cm. The unique lock cylinder greatly increases the security of the door lock. Package includes: 4 pieces greatly increase the security of the door lock