It was the first U.S. nuclear weapon designed from the start to avoid accidental detonation, with the use of "insensitive explosives" in the trigger lens system.

Its layout is similar to that of the smaller B61, with the warhead mounted in the forward part of the weapon to make the bomb nose-heavy.

Security features include next-generation permissive action link (PAL) and a command disablement system (CDS), rendering the weapon tactically useless without a nuclear yield.

Although its yield is lower at 360 kilotonnes of TNT (1,500 TJ), it incorporates guidance features of the B61-12 for better accuracy while being more powerful than that version to strike harder and large-area targets.

The actual nuclear explosive package, judging from published drawings, occupies some 3 to 4 ft (0.91 to 1.22 m) in the forward part of the bomb case.

Six such warheads, configured for the maximum 1.2 megatonnes of TNT (5.0 PJ), would be deployed by maneuvering space vehicles to "knock" an asteroid off course, should it pose a risk to the Earth.