Fist Ring

From Zelda Wiki.org

In both Oracle games, the Fist Ring is found randomly in a Gasha Nut or by bumping into Maple. When this specific Magic Ring is worn, it allows Link to punch when either the A or B button is unequipped. Its function is similar to the Expert’s Ring, but only one button has to be unequipped. Since his fists are less effective than Link's sword, the only conceivable purpose of this ring is to make the game more challenging, similar to the Cursed Ring.