Brass body. Brass shackle. 4 levers. Lever position 5 pushes the runner plate. The left keyway is for the servant key. The right keyway is for the master key. Rotate servant key 180 degrees clockwise to open lock. Rotate master key 180 degrees clockwise to open lock. The lock snaps shut. The master keyway is smaller than the servant keyway. The servant gates can be over pushed. There are no master gates. The lock does not match the patent exactly.Patent #169886. More… Show Mechanicals