Big Fisted Belt is a cursed Girdle of Hill Giant Strength. It sets strength of the wearer to 19, but also sets their intelligence score to 6. It can be found at the Cloudpeaks temple (part of Rasaad's quest) inside a locked chest in the acolytes quarters.
Once equipped it can only be removed by a Remove Curse spell.
|“||Cursed Girdle of Hill Giant Strength: Big-Fisted Belt A fist-shaped brass buckle secures this belt of thick elk hide. The old bloodstains on the leather hint at unspeakable carnage, but the misspelled graffiti scratched into its surface suggests that the girdle's former owners were none too bright.||”|