These are 5mm x 11mm 12v 80mA. Class 101 and any other Hornby loco with a similar sized bulb. Your original bulbs may be fractionally larger or smaller than this size, but these will fit many locos including.
10x 12V E5 LES Miniature Filament Replacement Screw For OO 00 Scale Bulbs S.8718
Marklin 4 x 600150 Replacement Bulbs 19 Volt BA5 Socket - NEW
Warm White LED bulbs 18 volt light bulbs For Lionel American Flyer 10 pack
External sensors for Speedometer (v211 and up) for many popular scales
