What is the fine-grained topic of the following text: The Metal Double Doorframe is treated as a metal structure and can only be damaged by explosives, the Tek Rifle, Tek Saddles, a Titanosaur, Arthropluera, Corrupted Creatures, Enraged Creatures, Titans, Bosses, or the DodoRex. Only return the topic.
Metal Double Doorframe durability and damage in a game