Bang snaps

Bang snaps (also known as Throwdowns, snap-its, poppers, poppies, pop-its, snappers, whip'n pops, Pop Pop Snappers, whipper snappers, fun snaps, party snaps, pop pops or snap'n pops) are a type of small novelty firework sold as a trick noisemaker.

Bang snaps consist of a small amount of gravel or coarse sand impregnated with a minute quantity (~0.08 milligrams) of silver fulminate high explosive and twisted in a cigarette paper to produce a shape resembling a cherry. The friction-sensitive silver fulminate detonates when stepped on, ignited, or thrown on a hard surface, producing a sharp salute similar to that of a cap gun.

Despite producing a legitimate (albeit tiny) high-explosive detonation, the extremely high mass ratio of gravel to explosive acts as a buffer to ensure that the devices produce only the audible "crack" of the supersonic shockwave; they are incapable of producing physical damage, even if discharged directly against skin, and the detonation frequently fails to even break the thin paper holding the ingredients. The explosion is also too weak to propel the gravel any distance, which usually falls to the ground. This makes them safe for use as a children's toy, for which purpose they have been widely sold around the world since the 1950s. They are also a common part of Chinese New Year celebrations.

Bang snaps are primarily produced alongside other export fireworks in Brazil, Korea and China and are widely available over the counter at small toy stores and shops specializing in jokes, novelties and magic tricks. The snaps are typically packed in sawdust to prevent them from discharging due to rough handling while in transit.

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Wikipedia