H11A vs H11B / H7A vs H7B
It's important to select the right version of HID, but which one do you need?
Why does it matter?
Because HID has a return wire by design, this wire can interfere with the beam from your headlight projector or reflector, causing a dark spot which results in reduced output. The reason is due to the difference between Halogen and HID. Halogen bulbs do not have a return wire, so it does not matter. Once you upgrade to HID, you need to ensure you pick up the right version. See below for details.
So do I need A or B?
H11A vs H11B HID Bulbs
*images provided by Morimoto
Typical Configurations
**It's best to double check the actual headlight!**
| Projector Style | Low/Main Beams | H11B* |
| H7A* | ||
| High Beams | N/A | |
| H7B | ||
| Reflector Style |
Low/Main Beams | H11A |
| H7A | ||
| High Beams | N/A | |
| H7A |
*Kia/Hyundai will normally use H11A & H7B for their main beam projectors
General rule of thumb: Typically in a Reflector style headlight, the return wire would be facing down (on the bottom) in the low beam, and up (on the top) for the high beam. In a Projector, the return wire would normally be facing down. If the wire will wind up towards the side (large opening or tab opening is towards the side), it's best to have the return wire facing towards the recommended direction as described above.
H11A is considered the opposite/uncommon, but it really depends on your vehicle. H11B is also referred to as H11 in the HID world. You'll need to remove your original Halogen bulb, and see which way tabs are facing. Alternatively, you can do some searching online for your vehicle, as every make and model is different. Since HID conversion are so popular, there is bound to be somebody else out there asking the same question, such as on automotive forums.
Still confused? We can help!
If you have any further questions please drop us a line and we can help determine what size is needed for your ride!