The Girdle of Feminity/Masculinity was a magic item which the Order of the Stick looted from some dead ogres in the Dungeon of Dorukan. According to Vaarsuvius, "the belt contains a complex enchantment that transforms the wearer into the opposite gender". Roy Greenhilt decided to leave it behind, calling it a piece of crap, but Elan retrieved it ("cause I was curious").
Roy would later don the item in the Weary Travelers Inn and Tavern in order to save Elan, who was poisoned by assassins attempting to kill the King of Nowhere. After the skirmish, the Girdle was removed by Durkon Thundershield's Remove Curse.
Vaarsuvius did not appear to see or comprehend the effects of the Girdle.