This is a swing bar lock. Typically these are used as a secondary door lock in hotel rooms. It is constructed zinc and comes in a chrome plated finish. Secures your door while allowing 2 in. of viewing or ventilation. They are easy to install. Can be used as a child safety lock if installed high enough for your children to not be able to reach. All the necessary mounting hardware is included for a quick and easy installation. A Phillips head screwdriver is required for installation.