The Ring of Tulkas
+4 strength, dexterity, constitution. Provides resistance to fear. Cannot be harmed by acid, electricity, fire, cold.
When activated, it hastens you for d75+75 turns. Takes 151 to 300 turns to recharge.
Min Level 70, Max Level 127, Generation chance 2, 0.2 lbs

(Angband 3.1.2v2)