While wearing this helm, using your action to open a door or use any similar mechanism creates an invisible, undetectable, see-through portal with the same width as the doorframe that links that doorway to another random doorway within a range of 500 feet. The exit doorway must have a similar size and shape to that of the entrance doorway. Using your action to close the door closes the portal, and removing the helm closes all portals created by the helm.

Notes: Teleportation, Headwear