link: http://www.gacoshop.com/index.php/arma-2-combined-operations-steam-gift.html
The ARMA 2: Combined Operations pack includes the award-winning ARMA 2 and the stand-alone expansion; ARMA 2: Operation Arrowhead. Combine the new features, weapons, units and vehicles of Operation Arrowhead into the original ARMA 2 for the ultimate military simulation experience.

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