Star Wars Armada: Rebel Transports - Rules of Play says:
The Rebel Transports Expansion Pack introduces a flotilla of GR-75 medium transports to your games of Star Wars™: Armada. In addition to its flotilla, which you can field as either a pair of GR-75 Combat Retrofits or GR-75 Medium Transports, the Rebel Transports Expansion Pack introduces eight upgrades, four of which feature the utilitarian Fleet Support icon. Relay commands to your larger ships with a Comms Net, or trail behind your largest ships with Repair Crews to keep them in the fight a bit longer. Clever use of the support your fleet gains from its Rebel transports can easily make the difference between victory or defeat.
The Rebel Transports Expansion Pack contains two GR-75 medium transport miniatures, two ship cards, eight upgrades, one rules reference card, and all necessary components.