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U.S. Marines with 2d Combat Engineer Battalion, 2d Marine Division (MARDIV) and Dutch Marines with Marine Squadron Carib, Netherlands Marine Corps detonate a breaching charge during Exercise Caribbean Urban Warrior on Camp Lejeune, North Carolina, March 13, 2023. Exercise Caribbean Urban Warrior is a bilateral training evolution designed to increase global interoperability between 2d MARDIV and Marine Squadron Carib. (U.S. Marine Corps photo by Lance Cpl. Eric Dmochowski)

Note: The flash in the picture is almost certainly shocktube, a type of non electric initiator. It is made up of a thin, flexible, hollow tube that contains an extremely small dusting of high explosive. When initiated, the explosive shockwave travels down the cord nearly instantly until it reaches the blasting cap on the other end.