A High Explosive Bomb is a general-purpose munition for destroying targets. HE bombs typically have a thick-walled casing, and less than half its weight in explosive filler. Altogether the bomb can inflict damage through explosive blast, penetration (after falling from a great height), and fragmentation from the casing. Air-dropped bombs were developed shortly after the development of aircraft. These often use contact fuzes, while some "daisy cutter" types may have a protruding standoff to ensure explosion slightly above ground.