ROKS flamethrowers 1935,"Soviet Union"The ROKS-2 and ROKS-3 were man-portable flamethrowers used by the USSR in the Second World War. The ROKS-2 was designed not to draw attention so the fuel tank was square and resembled a regular backpack, and the nozzle looked like a service rifle. The propellant tank was a small bottle underneath the backpack fuel tank. ROKS-3 was a simplified design and had a regular cylindrical fuel tank.