Premium Material: 304 stainless steel latches and 202 stainless steel screws. Corrosion resistant, high toughness, rust protection. Durable enough to help protect children and pets. 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 space between the window and the window frame should be 14-17mm. Maximum opening: The window can be opened normally when the vent is unlocked. Once fixed, the window can open up to 65 degrees. Helps prevent children or pets from falling out. Wide usage: These window restrictors are suitable for home, nursery, school, and other applications. Contents: 1 spacer for left-handed and 1 for right-handed, including 8 screws. 100% money back guarantee: If you are not satisfied with your purchase, please . We will provide the best solution.