High-quality materials: thick stainless steel, rust-proof and corrosion-resistant. Surface treatment, beautiful appearance. Heavy-duty latches are used for interior doors and are durable. 【Improve safety】The metal chain can only be removed by pressing the button. This is a very safe design. The person outside the door could not reach out to remove the metal chain. Easy to install: It can be installed on any wooden door, using screws for installation, no other installation steps, easy and quick. 【Thick metal chain】The thickness of our metal chain is excellent! The thickness of 2~3mm is extremely strong and absolutely safe under all conditions. No need to worry about bad guys breaking in. Wide application: The surface mounting and narrow design make the door chain easy to install on any door size. Whether thin or narrow, the door frame is placed above or beside the door frame with minimal effort and tools.