Abstract: A safer flash-bang grenade that yields the state of the art sound intensity, plus a brighter, more intense flash of the order of 13.5 million candela—which effect is due to a combination of a particularly efficacious pyrotechnic formulation and a particular reaction chamber design that momentarily retains or holds-back the reaction escape until the desired intensity is reached. The particular pyrotechnic formulation is based upon a strontium nitrate oxidizer in conjunction with an aluminum powder metallic fuel and a sulfur non-metallic fuel. The particular reaction chamber design includes a relatively rigid, non-fragmenting charge holder, with a slip-fit thin aluminum sleeve internal thereof and a shrink fit or other sealed sleeve external thereof.