A side curtain air bag module includes an inflatable cushion and an inflator. The inflatable cushion includes a first panel coupled to a second panel. The inflator is configured to inflate the inflatable cushion. The first panel and the second panel are joined generally continuously at a peripheral edge to form a first inflatable chamber. The first panel and the second panel are joined at a central location to form a second inflatable chamber that is in fluidic communication with the first inflatable chamber. In a stored configuration, the first inflatable chamber is rolled in an outboard direction, and the second inflatable chamber is rolled in an inboard direction generally around the first inflatable chamber.