A lockbox attaches to a doorknob with a shackle that locks in place. A small containment chamber secures with a combination lock. A house key or car key might be stored inside the lockbox. Typically a lock box is used to make a house accessible to real estate agents. The lockbox hangs on the door of an unoccupied building, with the key to the building locked inside. Agents can acquire the lockbox combination from the listing company and remove the house key in order to show the property to clients.

Step 1

Dial the correct combination of numbers on the rolling display. A lockbox may have three or four numbers in the combination.

Step 2

Slide the latch button. The latch may slide up or down, but it will only move in one direction.

Step 3

Release the door. The door will pop open when it's pressed at the lower end.