device shown therein comprises a support member 10 a plurality of led holders 11 supported by the support member 10 and two spiral elements 12 and 13 the support member 10 is in the form of a tightly wound spiral which is punched out of sheet material typically plastics material or an aluminium alloy and which is capable of flexing for a purpose which will become apparent hereinafter the support member 10 is mounted in a retaining bowl 14 and has its outer peripheral edge secured to the lip of the bowl 14 the led holders 11 are connected to the support member 10 by universal joints 19 so that the holders 11 can pivot relative to the support member 10 each holder 11 has two eyelets 15 and 16 the eyelet 15 has an elongate horizontally extending slot 17 and the eyelet 16 has an elongate vertically extending slot 18 the first and second elongate spiral elements 12 and 13 typically formed from relatively rigid wire are wound through the eyelets 15 and 16 respectively the spiral element 13 is not attached to the eyelets 16 but is slidable relative thereto and is rotatable relative to the support member 10 by an electric.