The ROKS-2 and ROKS-3 (Shortened from Russian, Rantseviy Ognemyot Kluyeva-Sergeyeva; àðýÃÂõòÃÂù ÃÂóýõüÃÂàÃÂûÃÂõòð â áõÃÂóõõòð; "Kluyev-Sergeyev backpack flamethrower") 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 and gas tanks were concealed under a sheet-metal outer casting resembling a knapsack; the flame projector was designed to resemble a standard MosinâÂÂNagant rifle. The purpose of this was to prevent the operator from being specifically targeted by the enemy. The flame shots were ignited by firing specially modified 7.62ÃÂ25mm Tokarev cartridges.
The ROKS-2 was used, amongst other engagements, during the close-range fighting during the first days of the Battle of Kursk in 1943.
The ROKS-3 was a simplified model designed to be easier to manufacture. It did away with the disguise for the backpack, though it retained the flame projector designed to resemble a rifle. Both models carried around of fuel. The fuel was propelled by nitrogen gas pressurized at and, under ideal circumstances, had a maximum range of around .
The Finnish designation for captured ROKS-2 units was liekinheitin M/41-r. Captured Soviet flamethrowers saw some use by Finnish forces during the Continuation War. They were operated by two-man teams of combat engineers. They were well regarded by the Finns, although flamethrowers of all kinds saw little use by Finnish forces.
Some ROKS-3 units were supplied to North Korea, Czechoslovakia, Kingdom of Yemen (via Czechoslovakia), and North Vietnam.