The Iron Helm of Knowledge [6,+20]
A large helmet that can protect the entire head. Ventilation and bad
vision can be a problem, however.
This helm, designed by Petty-Dwarves ages ago to act as the brain of a
long lost project, is made of finest glass. Its light banishes all
secrets, and makes audible whispers from the deceased.
It can be activated for whispers from beyond(sanity drain) 100+d200
turns if it is being worn. It provides light (radius 1) forever. It
decreases your luck by 6. It identifies all items for you. It cannot
be harmed by acid, cold, lightning or fire.
Level 20, Rarity 5, 7.5 lbs, 100000 Gold

(T.o.M.E. 2.3.5)