The UBK is used to attach Maglock L brackets, Architectural Z & L brackets and various lock housings to glass doors and transoms.
Example:
The UBK P would be used for the L bracket above the door and a UBK U for the armature on the door for an outward opening door (A), however for an inward opening door (B) a second UBK P would be required to fit the Z bracket too.
