If a portal of the same color is already placed, it will be closed and the new one will be used instead, limiting the player to the use of only two portals at a time.
If a portal of the other color is already placed, these two portals will be linked.
If the projectile strikes a valid surface, a portal of the corresponding color will be formed. When the device is fired, a burst of energy will be released from the end of the device. The Handheld Portal Device is designed to create and place portals on immobile surfaces, or surfaces covered with Conversion Gel that are big enough for the Portals to be opened.