These Triad square slimline deadbolts can be fitted over pretty much any existing hole and come with a 10 year guarantee.
 
Variant: Key/Turnthumb (key on outside, snib on inside)
 
Height: 65mm
Width: 65mm
Projection: 20mm
Backset: 60mm or 70mm (adjustable)
 
Material: Zinc Alloy & Steel
 
Screws: Included
 
Brand: Zanda Architectural