I was quite interested in the comments and decided I would buy one as I my neck does not seem to turn as well as it should, perhaps WD40 might work!

Damn, why are there so many things NOT available in the UK.

Anyway, at least I have been able to find one on ebay USA. Not sure if the price is good or not, $8, sound reasonable to me.

BUT before I click on buy, I am not sure which one to go for:

COMPACT, which extends 50 millimeters and has a mirror size of 20x37 millimeters (HxW)
NORMAL, which extends 85 millimeters and has a mirror size of 28x37 millimeters (HxW)

Be very grateful for any advice.