Architectural quality UK manufactured by Imperial locks and latches made to BS EN 1634-1. Horizontal mortice latchbolt operated for door knobs either side, compatible with our glass knobs. Deadbolt operated by key from either side. 2 way action and sprung. Supplied in satin brass also available in all our plated finishes. The centre is the measurement where the spindle is fitted, allowing enough room for hand clearance, if you need advice please contact us.