Function is determined by sliding snib on forend. When the snip is in its up position, the lock will deadlock when the door is closed and can only be opened by a key or by the thumbturn. When the snib is in its middle position, the lock will latch normally, but can be opened by the handles as well as the key and the thumbturn. When the snib is in its down position, the latchbolt is retained inside the lock case. Microswitch version. The switch changes its status when the bolt is fully extended. The lock case works with the 4613 and 4614 striker plates.