The most sophisticated outdoor lounging system ever produced, MU combines the seating technology, modular logic and more compact proportions of the best indoor systems with the lightness, strength and weather-resistance.. With extra-thick cushions and ultra-light Batyline® interior support, the MU Left module XXL offers indoor comfort and unprecedented modularity for an outdoor design. Frame Maintenance: Clean with a soft cloth and warm water. Cushion Maintenance: All cushion covers can be removed and washed.