Material Made of high quality material, can withstand higher pressure, not easy to damage. Excellent safety High quality choke cable for increased safety, health and safety in the home and baby/child safety. Easy to install Made of steel wire measuring 19cm long, comes with self-tapping screws and wrenches, just a screwdriver or drill to install. Very useful Ideal for PVC, aluminium, wood, composite doors and windows. Use on double-hung, ribbed and sliding windows; balcony doors, guest room doors, etc. Locked and unlocked Special restricted design provides 19cm restriction and fresh air, and the window can be fully opened when the cable is pulled out at one end with the wrench. Once the cable is in place, the distance that the window can be 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, greatly increased the security of the door lock. The packaging is bland: 4-pack We not only provide high-quality products, but more importantly, we provide you with a long-term after-sales guarantee. When you buy our products, you get a full range of after sales support, so you can shop with confidence and satisfaction.