The 85mm M1944 air defense gun (or "Model 1944" and also known as "KS-18") was nothing more than the original M1939 platform engineered to fire a more powerful charge and thusly offered up improved all-around battlefield capabilities. The type was pressed into service in 1944 and quickly overtook the original M1939 series on the Soviet production lines. Outwardly, the M1944 was more or less the same gun platform and it was the ammunition charge that truly set it apart from the original.
Like the M1939 before it, the M1944 could be towed into action with its four-wheeled carriage system. Once in place, the gun could be elevated to suit the target - be they air or land-based - thanks to its 360-degree traversing gun mount with +82 and -2 degree elevation specifications. Like the M1939 (and the German "88" for that matter), the M1944 retained full anti-tank capabilities as well as being an anti-aircraft weapon. For this role, the crew could switch to an anti-tank projectile.
M1939 systems became a battlefield prize for the German Army and the M1944 proved no exception thanks to their effectiveness on the battlefield. Captured gun systems and their ammunition supplies were reconstituted back into German Army service to be used against their former owners, often times alongside their 88mm guns for a truly dastardly effect. In this German guise, the guns came under the designation of 8.5cm Flak M.44(r). Still others were sent back to Germany, rebored to accept the standard 88mm projectile and set up in the homeland defense role under the designation of 8.8cm Flak M.44(r).
The M1944 survived the war and was fielded extensively across the Soviet sphere of influence during the Cold War. Examples were still in operation by the time of the American air war over Vietnam. The system can still be found in the inventories of several nations even today.