2008 Chevy Avalanche fog light bulb size?

[Crni]

I want to change the fog lights on my 2008 Chevy Avalanche to HID's and need to know the size of the bulb... I called a nearby dealership but they could not help me. Does anyone know the size? Thanks!

[boysrustimes3]

Maybe this will help!

http://www.autozone.com/Ntt,Fog+light/shopping/accessoriesResults.htm;jsessionid=F0E370B7811DBAB6 BCAB9C67514C9F9B