Guthan's helm

Guthan's helm is melee armour worn in the headwear slot that is part of Guthan The Infested's set of barrows equipment. To wear Guthan's helm, a player must have 70 Defence. Guthan's helm is tied with Torag's helmet for being the strongest helmet in the game. However it is much more expensive than Torag's helmet. Also note that while wearing Guthan's Helm and interacting with any Minotaur summoning familiar, it will state that it's been offended by the horns on your head.

Being part of Guthan's barrows set, if Guthan's helm is worn along with all of the other pieces of equipment in Guthan's barrows set the player receives a special attack. Successful attacks have a chance of replenishing one Hitpoint for each damage the player deals. This piece of armour cannot be made using the Smithing skill.

Despite Guthan's having more than average combat stats, it is mostly used by players to heal (and saves space that would have been used bringing food) and then they revert back to their regular melee armour. This method saves money and ultimately puts off having to repair the armour as regularly.

Repair
Barrows armour can be repaired cheaper if the player has an armour stand in their house, but it depends on their smithing level.  * - Guthan's helm is only tradable when undamaged or fully broken.