The CBU-100 Cluster Bomb (also called the Mk-20 Rockeye II) is an American cluster bomb which is employed primarily in an anti-tank mode. It weighs 490 pounds and carries 247 Mk 118 Mod 1 bomblets. The anti-tank cluster bomb is an air-launched, conventional free-fall weapon. The Mk 20, CBU-99, and CBU-100 are used against armored vehicles.