Immovable Rod

This flat iron rod has a button on one end. As an
action you can press the button, which causes the
rod to become magically fixed in place. Until you
or another creature uses an action to push the
button again, the rod doesn't move, even if it is
defying gravity. The rod can hold up to 8,000
pounds of weight. More weight causes the rod to
deactivate and fall. A creature can use an action
to make a DC 30 STR check, moving the rod up
to 10 feet on a success.