The JS-2 (IS-2) was developed from the KV heavy tank. It was classed as a heavy tank but weighed only 46 tonnes: a Panther medium tank weighed 45 tonnes.
Armour was excellent and it mounted a 120mm gun that was intended mainly for bunker busting. The gun was not especially high velocity but the heavy shell would smash up enemy tanks even if it didn't penetrate. The gun was slow to reload, which wasn't a problem as enemy bunkers weren't going anywhere.
The model is in Red Army 1945 Battle of Berlin markings. I slapped the white marker on as if it had been roughly painted by a tanker with a whitewash brush.
A very good tank that soldiered on into the Cold War.