Overview Reviews Similar Products –> Product Description 12v 21w single filament bulb. Most commonly used bulb in taillights, also found in some headlights. Check your size before ordering. BA15s or 1156 Base. Same bulb type. 25mm Dome od 15mm Base od Product Videos Custom Field Product Reviews Write a Review Write a Review Generic 12v 21w Light Bulb *BA15s / 1156 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *