Marks 9225F/5-W-LH Antique Brass US5 F Function Left Hand Single Cylinder Lever Rose Ornamental Iron Mortise Lockset, specially designed as a dormitory panic proof lockset that unlocks with key on the outside, or the lock opens by rotating the inside Lever which throws the bolt back into the mortise body, without turning the thumb turn, and shifts the rocker, so no one can get back in without a key, that is why it is called a dormitory mortise lock. This commercial mortise lock features a 2-1/2" backset, a 1" deadbolt, a 1" x 7-1/8" front face plate, and it fits doors 1" inches thick. This lock is ideal for a dormitory or a place where an ease of exit is needed.

Dormitory (F Function) Mortise Lockset: A mortise lock that unlocks with key on the outside, and on the inside it unlocks with one touch, by either rotating the knob or the lever from the inside, without turning a thumb turn, it throws the bolt back into the mortise housing, and then it shifts the rocker preventing an unwanted intruder from entering through the door. Ideal for a dormitory room, or an exit door where you want several people to be able to leave and the lock should lock automatically, so strangers can't enter without a key.