For Thicker Doors Between 45mm (1-3/4") - 57mm (2-1/4")
For Use with ULTRALOQ U-Bolt Pro Series and U-Bolt Series Smart Lock
Note: The backup key is for the extended cylinder, which is suitable for thick doors between 1-3/4" - 2-1/4" in thickness. Please also replace your current screw D with the longer one.