Features: The Front Door Chain Helps Identify A Caller Before The Door Is Fully Opened. It Provides Enhanced Front Door Security And Has An Easy To Release Chain When The Door Is Closed. Enhanced Safety: A Strong And Durable Door Lock Chain Made Of Solid Steel That Restrains Against Forced Entry To Your Home. A Must Have Feature To Protect Yourself And Your Family. Elegant Finish: This Door Restrictor Is Finished In Polished Chrome Throughout Which Complements Other Door Furniture. The Narrow Design Means It Can Be Fitted To Any Door Type And Size. Easy To Fit: The Surface Mounted Installation And Narrow Design Allows This Door Chain To Be Fitted Onto Any Door Size With Minimum Effort And Using Simple Tools. Fixtures And Fittings: All Fittings Are Supplied Including Colour Matched Screws For Quick And Easy Installation. Please Refer To The Images For Detailed Product Dimensions.ZF Notice:1. The monitors used are different, the computers are different, and the camera angles are different, there may be problems with the angle and color.2. Purely manual measurement, there may be 0-1cm error.