An expansion to Nations at War: White Star Rising, adding a range of new units [110 counters] and 14 new scenarios.
From the LnLP webpage...
"White Star Rising: Operation Cobra is an expansion for the game White Star Rising in the Nations at War series. This expansion focuses on the events surrounding the Allied breakout from the Normandy beachhead over the course of a month in July-August 1944. White Star Rising: Operation Cobra adds the Canadians, the Free French, and the Free Polish to the Nations at War series in addition to new units for the Americans, British, and the Germans.
White Star Rising: Operation Cobra comes with nine stand-alone scenarios, focusing on events near Falaise as the Germans tried to escape the converging allied armies. Among the topics are the Polish stand on Mont Ormel Ridge and Canadian efforts to capture the village of St. Lambert-sur-Dives. White Star Rising: Operation Cobra also contains a five scenario linked campaign following the breakout of American armored units during Operation Cobra at the end of July 1944.
White Star Rising: Operation Cobra is not a stand-alone game, you will need White Star Rising to play it."