You may have seen the blue box hanging on the doorknob of a home for sale. They are electronic lockboxes that usually hold keys. Local real estate agents can open them using the ekey app that works on smartphones.
The app has to be reauthorized every day so that unauthorized persons can not use it. Each time the box is opened the owner of the box can be notified and can get the identity of the person who opened it and the time it was opened.
The boxes can also be opened with an electronic key for those agents who do not want to use a smartphone app. The key is only available to members of REALTOR associations.
We can also program the boxes so that they can not be opened during certain hours like after 8:00 PM and before 8:00 AM. Homeowners can go to sleep at night knowing that no one can open the lockbox and get into the house.
If my home were on the market I wouldn’t want one of those combination lockboxes on it. I would want the security of an electronic lockbox.