The Yale 91 basic nightlatch security lock is key operated from the outside and lever handle operated from the inside. On closing the door the snib function (bolt hold back button) enables the latch to be held back. This lock is non deadlocking and is ideal for use in hotels. Supplied with 1109 Cylinder. The 91 basic nightlatch has a 60mm backset, this is the measurement from the edge of the door to the centre of the keyhole. Locks with a 40mm backset are normally used where there is restricted space, such as on a narrow glass panelled door. This Yale 91DMGPB has a hardened Case Finish in Dark Metallic Grey and the Cylinder is Finished in Polish Brass. The lock is covered by a 2 Year Guarantee and has a Standard Security Rating. Pack: Boxed. Yale LocksA21B2018