SECURITY LOCK – This swing bar lock is a security locking device for hinged swing-in doors, allowing a door to be slightly opened to allow safe viewing and ventilation CHILD-SAFE SECURITY DEVICE – This swing bar door 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 - Adding a security swing latch to your door is quick and easy; all installation fasteners, including plastic shim spacers for leveling, are included STRONG AND DURABLE – Constructed of zinc diecast with an antique brass finish, the security door lock is strong, durable, and sure to last DIMENSIONS - This locking bar is 3-7/8 inch bar length x 2-1/2 inch height and has a long, hinged bar, which folds over the closed door to engage the catch; for further dimensional information, please see the line drawing