Sometimes you want to send someone a gift to open at a specific time. Because this could be a very special gift and you don't hope she can open early. This lock is a physical electronic lock. It can set time but after can't changed time until the set time has timed out.
So need a lock, you can set time and it will be open in your set time. she only in your set time open when she got your send gift. When you got this lock, at first you can set a time in the future, the second you can take it locked your gift then send your gift to your friends.