SECURITY LOCKING DEVICE –This U 10304 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 a satin nickel plated finish and a 6 inch, 8-link welded steel chain It’s strong and durable and sure to last.PRODUCT INFO – The 3-5/16 inch U 10304 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.NOTE – Please refer to the line art for dimensions and compare with your needs before ordering