Mine has a chrome metal rectangular body and the end profile shows a semicircular profile to the 'glass'(plastic). It has its own switch. "Glass' is very yellow and cracked, switch is dodgy but recoverable. I cannot locate a manufacturere's identity but I dont think it is a Lucas product. I removed it 7 years ago and wonder if it should have a separate metal base which I have lost as the switch is rather exposed underneath and could be a hazard with the roof lining etc. Does anyone know its make etc? a source for a replacement 'glass'? or a suitable replacement 'look-a-like'? What size lamp should it take?