General description The Yale PM444 series security door bolts are designed for concealed (mortice fixed) installation into the door, featuring a bolt that throws into the door frame. This mechanism provides enhanced security and protection for your home. Finished in polished chrome, these bolts come with a 2-year guarantee and are supplied in packs of two, each including one key. Technical specifications Finish: Chrome Type: Security bolt Guarantee: 2 years Pack contents: 2 bolts + 2 keys Compatibility and accessories Designed for standard doors requiring concealed security bolts Installation Concealed (mortice fixed) installation into the door Requires proper mortice preparation for fitting Usage Operate with the supplied key to lock or unlock the bolt Provides additional security when installed on external doors