The Yale 81 rollerbolt nightlatch front door lock has a rollerbolt for pushpull action making it ideal to prevent accidental lock out Ideal for communal or flat entrance doors It is opened by a key from the outside and a turn handle operation from inside The 81 rollerbolt 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 10 Year Guarantee Case Finish Dark Metallic Grey Cylinder Finish Polished Brass Backset 60mm Supplied with 2 x keys Security Rating Standard