Defender Security U 9913 Chain Door Guard &ndash; Door Chain Lock for Door and Home Security, 3-5/16&rdquo;, Solid Brass Construction and an Antique Finish SECURITY LOCKING DEVICE  This U 9913 Chain Door Guard is a security locking device for doors, allowing a door to be slightly opened to allow safe viewing and ventilation. CHILD-SAFE SECURITY DEVICE  This door chain lock can also be installed out of reach of children so they cannot open the door by themselves, providing additional child-safe door security. EASY INSTALLATION - Installation is quick and easy  additional security for your home or office doors are within reach! Installation fasteners are included. DURABLE CONSTRUCTION  This chain door guard is constructed of extruded brass with an antique finish and a 6, 8-link welded steel chain. Its strong and durable and sure to last. PRODUCT INFO  The 3-5/16 U 9913 Chain Door Guard can be used on a variety of door types and can be placed over or beside door casing. It features a 6-inch long, 8-link welded steel chain and all installation fasteners necessary for complete install.