 The fuel–air explosive (FAE) is one of the best-known types of thermobaric weapons.Most conventional explosives consist of a fuel–oxidizer premix (gunpowder, for example, contains 25% fuel and 75% oxidizer), whereas thermobaric weapons are almost 100% fuel, so thermobaric weapons are significantly more energetic than conventional condensed explosives of equal weight.Their reliance on atmospheric oxygen makes them unsuitable for use underwater, at high altitude, and in adverse weather.