There are a lot of bad LED bulbs out there. That's in large part due to the way that LEDs generate light - they're more directional. It's easy to jam a bunch of LEDs on a stick and claim high lumen output, it's something very different to make sure the light is going to the right place. We don't want to see Miata drivers rolling around with bad foglights, that just hurts everyone.
These SLF bulbs are from Diode Dynamics and have a patented optical design that makes them work properly in your existing housings. This makes them a true plug and play and gives you light output you can use.
On top of that, they're designed to control heat as well as possible. Not just a big heatsink, they're designed from the inside out to channel heat to the base, where a microfan dumps it. This makes them last longer than other bulbs - they've got a three year warranty. They've gone through full OE-style reliability testing.
Also, the yellow variant is a true yellow - not a sickly green color. It uses three LEDs to combine for a proper yellow color instead of just trying to filter a blue LED.
The 9006 is the correct bulb for 2004-05 fog lights and is rated at 780 lumen. They'll fit the low beams as well but we recommend a higher lumen light for that. If you really want to go crazy, you can also use those high lumen bulbs in the fogs. Sold in pairs.
Like all our other Diode Dynamic offerings, they are designed and built in the US. Sold in pairs.