Asec AS1716 Rim Nightlatch (Non-deadlocking) 

The automatic latch bolt is withdrawn by key from outside and lever from inside.

The latch bolt can be retained in the locks case by the snib button (on latch)
Designed to replace 40mm backset rim night latches without little adaptation to door and frame.
Suitable for either hand door without adjustment. 

Mechanism : ASEC 5 Pin Cylinder. 
Cylinder Finish : Brass or Satin Chrome Plates
Case Finish : Dark Metallic Grey (DM),
Keys Supplied : 2  
Door Thickness : 32mm - 57mm.
Backset: 40mm (Distance from door edge to cylinder centre) Available in 60mm backset  AS1721 (see under "related products" at bottom of this page).

* Keying Options Explained

• Individually keyed (Standard) - locks have own keys (2 keys included per lock)
• Keyed Alike - All locks have same keys (2 keys included per lock)