After Russian jets harassed an American MQ-9 Reaper drone for better than two hours, the drone went on to take out Usamah al-Muhajir, an ISIS leader in eastern Syria. According to some reports, the weapon used in the airstrike was America’s secretive “Ninja Bomb,” or a Hellfire missile packing six deployable 18″ blades somewhat officially known as the AGM-114 R9X. Here’s an overview of this unusual weapon and why it’s so useful for counter-terror operations.