Abstract: A multiple filament lamp has one set of ends of all filaments connected to a common conductor and the end of another set individually connected to separate conductors. The conductors are mounted in a non-conducting lamp base with the common conductor projecting centrally beyond the bottom of the base, and the separate conductors recessed into the side of the base and equally spaced around its circumference. The base is slidable into a socket-adapter having an outer conducting shell defining standard electric socket screw threads fixed to an inner non-conducting cylinder that is recessed interiorly at the top to receive a retainer ring for engaging a similar recess around the top of the lamp base, and recessed exteriorly to receive a conductor contact spring for biasing a spring end extending through the non-conducting cylinder inwardly into separate engagement with the respective conductors recessed in the lamp base as the lamp and its base are turned in the socket-adapter.