The SSC-8 is probably similar to modern U.S. cruise missiles, with the ability for redeployment while in flight. It is entirely different from the Iskander, which is a ballistic missile with some terminal guidance capability.
The Russians claim the missile is necessary for a parity-in-kind with Asian nations that possess similar missiles, notably China. This actually has some merit. But it has a particular use with Germany: to create domestic stress in similar to that which occurred with the deployment of the Pershing II. Quoting from the accurate Wikipedia article, which I have redacted with ellipses (go read the article):
But, you might say, the SSC-8 is a Russian missile, while the Pershing was American. To Germans, they evoke a common fear: Germany, a compact nation, in the bulls eye of conflict. The shape of war in Germany is an old fear, dating to the founding of NATO. It is the idea that a war would not be fought on Germany’s borders. It would, the Russian missiles emphasize, be total, involving all of German territory at once.
The Russian claim of an Asian purpose does not grant them innocence of the European. One unit has been deployed to central Asia, while the other remains near Volgograd, within range of Germany. One of Henry Kissinger’s predictions, in Does America Need a Foreign Policy? (2002), was that Germany would drift towards the east. The Russians may hope that, with modern techniques of subversion, fake news, covert funding, etc., and less than solid commitment by the U.S. to NATO, they might pry Germany in that direction. And with Germany, the Baltic states would break off like brittle bone.
The technical details of the missile are unremarkable. But the payoff to Russia is worth breaking the INF treaty. The Russians may have a reasonable desire for parity with China. But the range of the Volgograd deployment says to Germany, “Here’s looking at you, kid.”
But not with love.