Rear Fog Light Bulb

[AdzCM]

Did a quick search and didn't find anything.

Does anyone know if the rear fog light bulb is a dual filament one i.e. its the brake light and the rear fog light, or is the rear fog light bulb a separate bulb?

Got the mot comig up and got a new fog light switch. It lights up but im unsure of the rear fog. I remember the last few mots they said its barely noticable when its on.

Adrian