Gauntlets of Crushing

The Gauntlets of Crushing are a pair of gloves that grant the wearer a +4 bonus to THAC0 and damage when attacking with fists.

They can be used by nearly every class, but they are mostly useful to monks.

Baldur's Gate II: Shadows of Amn

 * City of Caverns - Reward from King Ixilthetocal if you side with him and kill Prince Villynaty. They cannot be obtained by pickpocketing the king or by looting his body if you side with the prince.

In-game description
"A foreigner from the east who went by the name of Floating Bear become well-known though the Sword Coast. Unarmed and unarmored, he bested many powerful warriors. One night, in the arms of a lady of the night, he whispered his secret. His martial arts training was supplemented by the thin gauntlets he wore, which allowed him to hit more accurately and with harder punches than bare fists would normally allow. The woman stole the gloves and took the next boat out. Floating bear soon left, returning to his homeland."