This particular bomber that uses stealth tehcnology is the only combat aircraft in the U.S. Army capable of carrying the 14,000-kilogram bomb.
GBU-57 was first tested in 2009. The precision-guided, bunker-buster bomb is much heavier than its predecessors; it uses GPS navigator to seek and destroy the enemy bunkers hidden deep under the ground.
MOP is often disambiguated with another famous explosive device, GBU-43B Massive Ordnance Air Blast (MOAB), which often comes with the alias Mother of All Bombs. This bomb weighs almost 10 tons, and is used for the same purpose as MOP.