By 1944, Allied air superiority was causing real problems for German armour and Heinz Guderian requested a more effective weapon. The result was the "Kugelblitz" (Ball Lightning) which mounted twin 3cm MK103/38 in a dual mount turret. Largely unchanged, the Pz IV had a Tiger turret race fitted allowing the sphere mantlet to rotate in a low open topped turret.The 3cm MK103 was adapted from the aircraft gfun and was capable of firing at 650 rpm. 2 Kugelblitz were delivered before the end of WWII.