The ARC Trooper Captain outfit set can be obtained by purchasing and completing The Pirate Captain Card Commander Campaign level for 500. In addition to those requirements, you must also have already completed The Supreme Commander and The Dark Lord Campaign.
The ARC Trooper Captain outfit set resembles standard ARC Trooper armor with several red and grey markings, similar to ARC Captain Burner. The gear set was based on the character Commander Hammer who appeared in the episodes "Clone Cadets" and "ARC Troopers" in Season 3 of the Clone Wars television series.