The Bathus full helm (Tier 2) is an item that can only be obtained and equipped while Dungeoneering. It requires level 10 Defence to wear. It may be picked up from the table at the beginning of a dungeon, obtained as a monster drop, or produced using the Smithing skill.
It can be produced by using 2 Bathus bars with a hammer on an anvil, requiring level 15 Smithing and granting 43 smithing experience.