Tail light / stop bulb LED 12 volt -ve earth (negative ground), red facing the rear and white around the sides. Direct replacement for original stop /tail light SMALL GLASS bulb used post war. Bulb has SBC Bay15d base and is shorter in overall length than the original bulb. Red LEDs shining through a red lens is brighter that a similar white LED. These bulbs draw so little power they can be run off a torch battery but the light output is greater. The light at the top (end) of the bulb is red and the side light is white, for the number plate. This model is only for a negative earth system. No changes to lamps or wiring required.
Original bulb number: 380 1157
SBC Bay15d = small bayonet cap, offset pin base, 15mm diameter, double contact (normal British tail/stop)