Nitro Cell is a defensive gadget in Tom Clancy's Rainbow Six Siege, Ubisoft's tactical shooter released in 2015. Because the gadget can be thrown and manually detonated for sudden kills, its audio became recognizable in gameplay clips, compilations and reaction edits across YouTube, TikTok and short-form gaming posts. Players often refer to it as C4 even though the in-game name is Nitro Cell. The sound remains popular because it instantly communicates a smart trap, a clutch denial or a chaotic surprise in R6 content.