Night Latch & Brass Cylinder from Basta. This standard night latch can be deadlocked on the inside and also deadlocked from the outside using a key, for increased security. The bolt can be held and withdrawn using snib. It is also suitable for both right and left handed doors. 

Key features:

• Can be deadlocked from the inside 
• Can be deadlocked from the outside using a key
• Suitable for both right and left handed doors