The GBU-57A/B Massive Ordnance Penetrator (MOP) is a precision-guided, 30,000-pound (14,000 kg) "bunker buster" bomb used by the United States Air Force. This is substantially larger than the deepest-penetrating bunker busters previously available, the 5,000-pound (2,300 kg) GBU-28 and GBU-37. It is designed to accomplish a difficult, complicated mission of reaching and destroying an adversary's weapons of mass destruction located in well-protected facilities. From Wikipedia
