Dual filament BAY15d replacement bulbs.
In automotive and trailer applications, these bulbs are used as tail (3 CP)/brake-siganl (32 CP) lights, with one or both filaments illuminated.
The 1157 bulb is the most commonly used. It is somewhat brighter and lasts longer than the 1034, in spite of the fact that they both have the same light output rating, and the 1157 has a higher wattage brake/turn signal filament.
The 1034 was commonly used in in older, pre-early 1970s vehicles.
• Pins are indexed, so bulb is oriented correctly in socket
• S-8 "B" shaped glass lens, with 1" diameter
• "standard" 15 mm base diameter
• Sold by the pair