Era 1730 Automatically Deadlocking Nightlatch, 60mm Backset, Suitable for higher security doors and shared residential buildings. Conforms to BS3621:2007, Automatically deadlocks when door is closed, Opened using a handle on the inside, or key from the outside, Can be held-open using the latch and snib button. 90 x 86 x 33mm (WxHxD)