2K215 -2 x 5mm x 15mm 12Volt 1.8watt  Screw In Tubular Bulbs MES (E5.5) - THESE ARE THE CORRECT SIZE FOR THE OLD HORNBY DUBLO STATION/YARD LAMPS AND WILL ALSO FIT EARLY HORNBY DUBLO/TRIX AND TRIANG HORNBY LOCOMOTIVES OR FOR GENERAL USE ON MODEL RAILWAY LAYOUTS - EITHER USE WITH BULB HOLDER (RECOMMENDED) OR SOLDER DIRECTLY TO THE BULB - ALSO FOUND ON SOME CLASSIC CARS