Demonslayer Arm (3.5e Equipment)
From D&D Wiki
Description: The Demonslayer Arm occupies the same space on the body as a glove. While wearing this, if you aren't demon or have the demonblood subtype, your total level is decreased by one, and you gain no benefit from Demonslayer Claws.
Activation: Activating the Demonslayer Arm is a swift action. The Demonslayer Arm is considered a one handed weapon. Deactivating it is a free action.
Effect: When the wearer makes an attack against a demon, or someone with the demonblood subtype, the arm deals an extra 2d6 damage. This is considered a natural weapon.
Effect 2: If you are tripped during your own trip attempt, you can deactivate the demonslayer arm to avoid being tripped.