Torque Tune Gear (SR10-EN018) - Structure Deck: Mechanized Madness 1st Edition

Once per turn, you can either: Target 1 monster you control; equip this card to that target, OR: Unequip this card and Special Summon it. A monster equipped with this card is treated as a Tuner, it gains 500 ATK and DEF, also if the equipped monster would be destroyed by battle or card effect, destroy this card instead.