Premium Material: 304 stainless steel latches and 202 stainless steel screws. Corrosion resistant, high toughness, rust protection. Durable enough to protect your baby and kids Easy to install: Just need a screwdriver to complete the installation (screws included). A window opener can be installed in about 5 minutes. Please note that the gap between the window and the window frame should be 14-17mm Maximum opening: The window can be opened normally when the window vent is unlocked. Once fixed, the window can be opened to 65 degrees. Effectively helps prevent children or pets from falling out Wide Use: These UPVC window restrictors are suitable for home, nursery, school, and other applications. Provides added security Contents: 1 left-handed and 1 right-handed spacer, including 8 screws Note: All measurements are manually taken; please allow 1-3 cm error. Due to lighting and display differences, slight color variations may occur. Actual product may vary slightly from image shown