Which Vacuum advance unit?

Hello All,

I have a 1.8 mk1 golf carb and I need a new vacuum advance.  I have seen 2 bosche ones on ebay but they are 2 different sizes on the operating lengths.  One is 45.8mm and the other is 52.6mm.

Does anyone know which I need to save me having to take it out of my car?

Thanks,
Natalie.

anyone??

i think you'll need to measure it, etka doesnt give size information