The orbs of protection are a quest item that players must recover during the Tree Gnome Village quest. They are stolen by a Khazard warlord during the quest and the player must find and defeat him in order to reclaim the orbs.
Once the orbs have been recovered the player must return them to King Bolren in the centre of the Tree Gnome Village maze.
Players cannot use the drop trick to keep a second one; if attempted, the chatbox will state You already have the orbs, and it will be deleted. Using Telekinetic Grab does not work either. Attempting to pick up any additional orbs after the quest, will delete the item and the chatbox will state King Bolren doesn't need anymore orbs from you.
For an exhaustive list of all known sources for this item, see here