Included is 3 x 120Ah batteries, a 40amp Enerdrive MPPT + DC-DC CHARGER 24V-12V, and 3 position battery tray. A standard 7 pin trailer plug will also fit this 12pin plug, so you will not need 2 units.
Requires a wiring diagram, and note what you require for pins 8,9,11 &12: eg What is it for.; Amperage required; and Ignition or Constant Power - Final Price will be dependant on the above.