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Home / Journal / H4, H7, H11, 9005, 9012, D2H: The Fitting Map for LED Headlight Bulbs

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H4, H7, H11, 9005, 9012, D2H: The Fitting Map for LED Headlight Bulbs

Most retrofit returns are fitment errors that a ten-second look at the old bulb would have caught. Here is how the eleven fittings we build actually differ, and which ones share a body so a mixed carton stays simple.

20 Oct 20268 min readNitskap

Fitting beats brightness

A high-output bulb in the wrong reflector is worse than a modest one in the right one — the housing was designed around a filament at a fixed point, and moving the light source moves the cut-off. Fitment is the first thing to verify, before wattage, colour temperature or price.

Three base families

Base familyFittingsWhat to check
H-series single filamentH1, H3, H7, H11/H8/H9Locating tab and keyway; H8 and H9 share the H11 base but differ in plug keying
H-series dual filamentH4Three tabs, clocked collar — a rotated collar kills the cut-off
US and Japanese9005, 9006, 9012, D2H9005 (HB3) and 9006 (HB4) look alike but are keyed differently; D2H is the HID-replacement base
H4 and D2H sit in a higher price band in our own catalogue because the base costs more to make. If a quote shows all eleven fittings at one price, ask which base is being substituted.

Four errors behind most claims

  • H8 sold as H11 — plug does not latch, contact becomes intermittent. Ship dual tails.
  • 9005 into a 9006 socket — the plug is keyed differently; forcing it breaks the tab and the beam is wrong anyway.
  • H4 clocked wrong — beam rotates, no cut-off, glare for oncoming traffic.
  • Decoder ignored — bulb-out warning on CANbus cars, and the return is filed as a quality claim.

One platform covering eleven fittings

Nine of our eleven fittings share a body and collar; only H4 and D2H need a different base. For a distributor that is the difference between stocking eleven part numbers with eleven spare-part boxes and stocking one family with two exceptions. It also means a mixed master carton can be assembled without opening eleven production runs.

A five-line sourcing checklist

  1. Confirm the fitting from the old bulb, not from the vehicle listing.
  2. State the market — colour and type-approval rules differ by country.
  3. Ask for the power and the cooling architecture together, never power alone.
  4. Decide decoder or resistor before the quote, not after the complaint.
  5. Fit one sample to the actual vehicle before the mixed carton ships.
Need a fitment check on a list?

Send your fitting list and market; we return which SKUs cover it, which base costs more, and a mixed-carton plan.

Request a quote

FAQ

Can an H11 bulb go into an H8 socket?

Mechanically on many housings yes, but the plug keying differs. Use a bulb supplied with both connector tails, or change the harness connector.

Is D2H a direct HID replacement?

D2H was designed to fit HID projector bases. It is not interchangeable with a halogen H7 or H11 socket — verify the base before quoting it.

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N13S

N13S 260 W · blue rear cap
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N15 240 W · red rear cap

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