The Mithril Chain Mail 'Belegennon' (-1) [28,+20]
+4 dexterity, stealth. Provides resistance to acid, lightning, fire, cold, poison. Cannot be harmed by acid, electricity, fire, cold.
When activated, it teleports you randomly up to 10 squares away. Takes 2 turns to recharge.
Min Level 40, Max Level 127, Generation chance 33, 15.0 lbs

(Angband 3.1.2v2)