Kairoseki Cuffs

Kairoseki Cuffs: A special handcuff made to arrest those with Devil Fruit users. The lock is made of seastones so when a devil fruit users are wearing them, they can't use their powers, it slowly drains the person's strenght but unlike other seastones, the person won't be deadwight until the cuffs are off. During the Enies Lobby Raid, Nico Robin wore them until she was free of it on the bridge.