 Other terms used for this family of weapons are "high-impulse thermobaric weapons" (HITs), "heat and pressure weapons", "vacuum bombs", or "fuel–air explosives" (FAE or FAX).In contrast to a condensed explosive in which oxidation in a confined region produces a blast front emanating from a single source, a thermobaric flame front accelerates to a large volume, which produces pressure fronts both within the mixture of fuel and oxidant and then in the surrounding air.Thermobaric explosives apply the principles underlying accidental unconfined vapor cloud explosions, which include those from dispersions of flammable dusts and droplets.