Mordenkainen's Key

You need to attune to this item in order to use it.
Once per day, you can cast Dispel Magic as a 6th
level spell.
The key silently hums if you hit is hit against something
The Archmage feared what could await him, so he
forged this key to safely lock away what could be found
in the far unknown. Even he did not expect that the
only discovery should be a endless expanse of azure.