Pouf, Stool, Ottoman - Or Simply the Basic Component for Probably the Most Flexible Sofa System in the World? The Curt single module is of course also a wonderful pouf. Or a useful ottoman. The Curt single module also makes a splendid simple, cosy stool. But the single module only shows its full potential when several of these modules are in play. The single module becomes a sofa seat, a back or armrest. A few separate single modules become an extremely flexible sofa system.