Lockwood Selector 4772 universal mortice lock with 89mm backset 4772SS Mortice Lock a pocket cut into the short edge of the door, allows a longer and thicker mortise box to slide into the door itself, providing superior protection. Mortice Lock Function - These locks have various latching functions which can be operated by key or handle outside and by turnknob, key or handle inside. All handing settings (Passage, Combination or Escape) can be adjusted via the hub selector under the face plate. Successfully tested up to 4 hours (depending on the type of doorset) on fire door assemblies by Australian Standard AS 1905.1- 2015, Part 1: Fire Resistant Doorsets. Holdback must not be activated on fire doors. Features: Easy Red /Green function setting. All lock settings are made from under the faceplate allowing for simple in-door configuration. Standard primary locks include anti-lockout and holdback capabilities (holdback is not suitable for fire doors). Operated by key or handle outside or by turnsnib, key or handle inside. Through-fixing of rose furniture turnknobs and escutcheons. Electric Strike compatibility. 15 mm stainless steel reversible latch bolt. Supplied less cylinder. Supplied with Selector 'V' cam. Compatible to most restricted keying systems. Specifications: Backset: 89mm Case Material: Zinc Door Thickness: 32mm - 50mm Fire Rating: up to 4 hours Finish: Stainless Steel Approvals: Security S7, Corrosion Security C6, Durability D8