Era Fortress Mortice Sashlock Brass 63mm Option:Brass 76mm The Double Locking Nightlatch is The Double Locking Nightlatch is designed to replace most existing front door locks The main lock bolt is 'automatically' deadlocked when the door is closed The British Standard High Security Mortice Lock meets the new BS 3621:2007 standard The British Standard High Security Mortice Lock meets the new BS 3621:2007 standard which meet the exacting demands of the insurance companies and the police 1000 key variations High security levels are delivered by a 20mm bolt throw on every lock All locks have hardened steel plates to resist drilling False notching in levers resist lock picking Interior & Exterior Material: Steel & Zinc Alloy Fixings included 10 year guarantee and warranty