Button

Stone Button
A stone button works much like a lever. However, it will revert the door back to its closed position after a short amount of time, unlike levers, which either stay open or closed. To use, you simply place one on a block adjacent to a wooden or iron door and then press with either right or left mouse. This opens the door for a short amount of time, long enough, however, for the player to make his way through. Remember that, if you want to open the door again from the inside, buttons will not keep the door open, so you should have a pressure plate or another button on the other side to get out of the room, assuming you are using an Iron Door.

Like levers, you can break the button with any tool, including your hands, and it will break quickly and give you back the button.