To decline an idea transforming it into a project. A wide range of variations allowing as many combinations for different uses. A development and extension of the UNO is offered as a highly versatile system. Seating system with elements, available in two depths to be combined together, with or without backrest and armrests of different shapes and functions, allowing a variety of compositions: corner, straight, island, with opposite seats. The units can be also used individually. The different units are assembled by means of linking plates which can easily be installed on the base frame.