Metal Material: The window support is made of aluminum alloy, which is thickened and has high strength. High-temperature Teflon baking paint, rust-proof, corrosion-resistant, shiny and more beautiful. Comes with free nail glue and small screws. Why Need It: It allows your home to be fully ventilated and allows you to control and adjust the window opening width as needed. Prevents babies from getting their hands caught when opening and closing windows without adult supervision; prevents toddlers from accidentally falling out of windows. It is effective not only for babies, but also for pets. Hook Design: The door and window opening and closing limiters adopt a hook design, which is more stable, not afraid of wind, and not easy to fall. More secure. It can control the window opening size from 53mm to 133mm. Upgraded Reinforced Rivets: After multiple high-strength tensile tests, it is not easy to deform and is strong and durable. Ideal for windy days, prevents windows from slamming or opening and increases comfort when using windows. Ensure the durability, durability and longevity of your door locks. Package includes: 1 * window limiter (165mm), 1 * metal fitting, 4 * screws. You only need a simple screwdriver to screw in, easy to use, no need to drill to drill.