DoorKing 1400 Lock Boxes DKS Lock Boxes provide Fire Department and Postal Carrier access through automated gates or doors for emergency or postal personnel. Fire Department lock boxes are designed for padlock (model 1400) or Knox KS-2 (model 1401) key switch operation. The postal lock box accepts the standard postal key lock. Fire Department and Postal lock boxes do not include the key switch or padlock. These must be procured from the respective authority.