D2, D2S, D2R, D2H — if you're doing a headlight retrofit with a D2-type projector, understanding the differences between these bulb types can save you time and frustration. Here's what you need to know.
Table of Contents
- Overview Video
- D2S and D2R Bulbs
- Using Standard Ballasts With D2 Bulbs
- What Are D2H Bulbs?
- Shop HID Bulbs at Ess K Customs
Overview Video
D2S and D2R Bulbs
All standard D2S and D2R bulbs use a socket-style connector on the base. D2S is the size used in projector-style headlamps, while D2R is designated for reflector-style headlamps. To power them, you use a D2S ballast — the same type found in factory HID headlights. These ballasts have a socket output designed specifically for D2 bulbs.
Using Standard Ballasts With D2 Bulbs
D2S ballasts can be slightly more expensive and are specialized for D2 setups only. If you want to use a standard aftermarket HID ballast (which uses AMP-style connectors) with D2S bulbs, you'll need AMP-to-D2 adapters. These adapters add the required socket to your standard ballast so it can plug into the D2 bulbs. Quality matters here — cheap adapters often result in a loose connection that causes lighting issues. A quality set will work reliably.
What Are D2H Bulbs?
D2H bulbs are an aftermarket solution that eliminates the socket connector entirely. Instead of a socket base, D2H bulbs have wires coming out of the base that lead directly to AMP-style connectors. This means they plug directly into a standard AMP HID ballast with no adapters or sockets needed. The socketless design also means a lower profile and more clearance behind the projector — a real advantage in tight retrofit builds.
Shop HID Bulbs at Ess K Customs
Working on a headlight retrofit and need D2H bulbs, D2S ballasts, or adapters? As an authorized Diode Dynamics dealer, Ess K Customs carries HID bulbs, ballasts, and retrofit components — with full manufacturer warranty.