The Azienda Energetica Municipale (Municipal Electricity Board) is situated in Milan city centre and, as both a generator and supplier of electricity, it wanted its headquarters to project an image of luminous, non-illuminated light at nighttime. The building, designed by the architect Cassi-Ramelli in the 1950s, has a smooth lower facade with a wide glass triple-height entrance and distinctive upper section decorated with tightly-knit pattern of architraved windows. A new concept of light and architecture was tested out. Working on the web of intradoses, light is taken to the very edge of the facade. A twin-lamped appliance was custom-designed in small numbers with a special optical device to control the fan-like 120° emission of light. The appliance was then "industrialised", patented and manufactured by iGuzzini (originally called "Edge" in its first version with a halogen lamp and then "Radius" that also used metal iodide lamps).