s3 8p 2009 oem front arb size please ?????

hi all
since brought my 2009 s3 1 month on I have changed few things mainly handling mods .
just want to find out what is the front ARB size on 8p s3 as I did some searches but it
only come up with the s3 8L size!!!please help!!as I know s3 8L front arb is 19mm but really can't
find any information about the 8p front arb size.
thanks for help
kam

p.s...so far I have .HPA haldex competition controller .bilstein b8 kw springs .034 top mount .adjustable front arb link.
whiteline 24mm rear arb .down size alloys from 19" to 18" team dynamic pro 1.2 matt black as 19 is too harsh for me !!

Anyone help???!

Can't believe no one know here!!!

Thanks Apparently is not just measure the diameter.!!!
Is something to do with the end bits!!???