The BLU-114B is a special-purpose weapon meant to attack electrical infrastructure such as transformers and distribution stations. It was originally used against Serbia in mid-1999; it is called a "soft bomb" because its effects are limited to the target, with little potential for collateral damage resulting from shrapnel or mistargeting.

Reportedly, the designation 'BLU-114B' actually refers to small submunitions, each about the size of a large aluminum can, which would be released from a cluster bomb (or possibly a specialized delivery system). Instead of containing explosives, however, each submunition is packed with a great deal of flexible, electrically conductive graphite filaments.

The bomb functions by scattering these filaments over power distribution equiment. When the filaments contact high-voltage equipment such as transformers, they vaporize and form short-lived conductive channels between existing conductors. Depending on current, this can cause arcing effects ranging from fires, to localized melting on the surface of the affected conductors, to large-scale explosions; in any case, the affected power distribution equipment is likely to be destroyed or rendered unusable.

Accuracy, when delivered using ordinary cluster bombs, is thought to be on the order of a few hundred feet. When originally used against Serbia, 70% of the Serbian power network reportedly went down. The BLU-114B is thought to be carried by the F-117A Stealth Fighter; specific information on costs, function and availability is classified.