The Pair of Leather Boots of Wormtongue (-1,-1) [2,+0]
+3 intelligence, dexterity, stealth, speed. Cannot be harmed by acid, electricity, fire, cold. Feather Falling.
When activated, it teleports you randomly up to 10 squares away. Takes 20 turns to recharge.
Min Level 10, Max Level 80, Generation chance 7, 2.0 lbs

(Angband 3.1.2v2)