Stackable chair with steel tube arms Uli Metal 331-M has a steel tube frame and an upholstered curved trapezoidal backrest in beech plywood, it can be customized with all lacquers visible in this file and in the Finishes section of our website or with sample colours, the slim bent seat is upholstered, customers can choose among COM or fabrics and materials from the Finishes section of our website.