Materials: SteelElectricity: CLI - E27 - ESL 15WWhy Doubles? Because they are very useful: over a bed, behind a sofa, above a work-surface.‎ And you only need one power point for two lamps ! And when what you need is a lamp to read by, take it from me – who has been living with it for the last few months – it is a significant contribution to domestic bliss: no more disputes about who gets the most light!