Game description from the publisher:
The IS-48 Super-Heavy Tank is perhaps the most powerful ground vehicle in the world. Armed with the brand new Heavy Tesla Gun, this tank is a dire threat to infantry and vehicle units alike. Designed by the SSU, the tank's deadly Tesla cannon ignores cover, wipes out out enemy squads in a single burst, and "explodes" for tremendous damage against enemy vehicles. When the IS-48 Super-Heavy Tank takes the battlefield, it instantly becomes the centerpiece of any army.
This versatile expansion allows for two builds of a single tank: the IS-48 Karl Marx or the IS-48 Lavrentiy Beria.