The 855 series features Key Wind operation which allows the door to be locked and unlocked by full rotations of the key.
The latch is retracted by the key or the handle.
Type 1 refers to 4 roller locks.
Operation: Key wind.
Latch reversal: Undo the screw in the side of the lock case adjacent to the latch. Remove the latch, reverse, reinsert and repace the screw.