Pair - stop light or tail light bulbs 6 or 12 volt, Pilot bulb for pre war headlights, approx 21W, very bright white light 6500K, Ba15s base, (single filament), parallel pins small glass equivalent (19mm max width, 35 mm max height). Polarity insensitive so it operates on negative or positive earth. Power consumption 6V: 0.22A. (A normal 21Watt bulb uses 3.5A )