The L-39 brass offset pivot hinge is employed when a minimum of visible hardware is desired, or when the door must swing free of its frame. It is mortised into the top and bottom of the door and frame; only the pivot is visible. The leaf measures 44mm x 10mm x 3mm. Offset pivot L-39 has a longer knuckle for wide throw conditions. The hinge is sold in pairs and installation instructions are available.