Gauntlet of Rust

Wondrous item, rare

If you are wearing this item and succeed on an unarmed attack against a creature wearing or carrying metal armor or a metal shield, the item takes a permanent –1 penalty to the AC it offers. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed. You may destroy nonmagical metal weapons per the rust monster’s Rust Metal trait if they are not being carried or held. You may also destroy, as an action, a 1-ft. cube of nonmagical ferrous metal that is not being carried or worn by touching it. Unlike most magical gauntlets, the gauntlet of rust does not come as a pair.