Long range self propelled howitzer.
Offense: Good against any ground unit as long as it stays out of their range. Can kill most infantry with a single shot and light vehicles as well. It isn't as durable as a tank but it has decent health for an artillery unit. If kept behind a wall of units it can turn the tide of the battle and if you can get three or four of them they will butcher any counter attack.
Defense: They can be countered by high health units, fast units that can take a hit or just about any unit in numbers. They also have no defense to air units so those are a very effective counter.
This is the armored variant so has the best defense rating. It also has slightly higher attack than the cheaper Manifesto.