The One Ring Dice Set: - Rules of Play says:
The One Ring Dice Set contains the seven dice for use with The One Ring Roleplaying Game; six 6-sided Success Dice and a 12-sided Feat Die, all packaged in a sturdy plastic box.
The One Ring Roleplaying Game uses a special set of dice: the twelve-sided Feat die, which is marked with numbers 1-10, as well as two special symbols, Gandalf’s rune and the Eye of Sauron, and a six-sided Success die, which is numbered 1-6, with a Tengwar rune on the 6.