This Lockmaster multipoint gearbox features a latch and deadbolt with a key wind feature. Case only unsprung.
To lock the door
1. On closing the door, the latch is automatically engaged.
2. Turn the key to throw and engage or "wind" out the locking points.
To unlock the door
1. Turn the key to unlock the door by "unwinding" the locking points.
2. A further quarter turn of the key will retract the latch.