 Some medium flatbed trucks carried the Soviet-made ZPU and ZU-23-2 towed anti-aircraft twin or quad barreled guns, as well as recoilless rifles and S-5 rocket helicopter rocket launcher pods.Some rebels have improvised with captured heavy weaponry, like BMP-1 turrets and helicopter rocket pods, as well as lower-tech methods such as using doorbells to ignite rocket-launched ammunition.Rebel technicals have also frequently employed BM-21 Grad rockets.