Vent Knob "B" - original? meaning?

[siennaman]

The new knobs on the fresh air vents all have a "B" on them - regardless of where they are bought. Is this original? My original never had a letter. Does it mean anything?

My guess is that this is just some knob that fits, and the originals had no letter.

[baws]

The knob(s) have several applications accross several makes of English cars. I believe the "B" denotes blower or fan, as I've seen them mounted on the levers that control heaters, fans and....vents.

[siennaman]

The knob(s) have several applications accross several makes of English cars. I believe the "B" denotes blower or fan, as I've seen them mounted on the levers that control heaters, fans and....vents.

Thanks - I wasn't aware it was a common part to other makes/marks - that explains it then.