The Cloak 'Holcolleth' [1,+4]
+3 intelligence, wisdom, stealth, speed. Provides resistance to acid. Cannot be harmed by acid, electricity, fire, cold.
When activated, it puts to sleep the monsters around you. Takes 55 turns to recharge.
Min Level 5, Max Level 100, Generation chance 3, 1.0 lbs

(Angband 3.1.2v2)