The seats are built of zigzag metal springs with ultra soft high-resilience foam, leading to immense comfort without any sagging as the years pass.Combination of perfectionist lines and elegant craftsmanship, Mix sofa utilizes bolsters for multiple purposes; When placed on top of the back structure, bolsters act as extra support for comfort. By placing the bolsters between the back cushions and the back rest, it acts as lumbar support or creates the perfect angle to lie-down.