S15 Stationary SofaOverview Indulge in the lush elements of the Knumelli stationary sofa. The cloud seat cushions are a hybrid pillow cushion design. They feature a supportive foam core that is generously wrapped with premium pillow fibers. Also, they are reversible and zippered. The loose, pillow backs are heavily stuffed with premium cushioning fibers that will wrap you in comfort. They too have zipper access for adjustment and personalization of your pillow fibers.