When an opponent's monster declares an attack on a monster you control: You can target 1 "Revival Jam" you control; switch the attack target to that target.
Rulings
Individual Card FAQs
If you have two "Revival Jams" on the field, you may redirect an attack to either one of your choosing.
If you have "Jam Defender", "Revival Jam", and a monster equipped with your "Ring of Magnetism" on your side of the field, you may redirect an attack to "Revival Jam" when you opponent attacks the monster equipped with "Ring of Magnetism".
Trap|
Continuous