Latch is automatically deadlocked when the door is in the closed position. All faceplates and strikeplates must be ordered separately. Reversible latchbolt withdrawn from either side by key or turn using any standard screw-in cylinder or thumbturn (with cam), or 4590 paddle handle (with 4580 cam plug). Also, range of lever handles available to suit. To operate holdback facility, push in bolt and secure by reverse turn of the key. This lockcase can be used as a direct replacement for the Adams Rite MS1850 Deadlock.