2005 widetrack arb sizes - help please.
 

Having found that one of the droplinks on my sti has a little bit of play in it I have decided to renew all 4 of them.

Also found my rear anti roll bar bushes to be worn, So looking to renew these too. Would prefer to fit powerflex items rather than standard bushes.
I would also replace the front arb bushes while I was under the car, But my question is what size should my arb bars be?

I measured it with a very cheap vernier caliper and they both look like 20mm front and rear. Does this sound correct?

I had expected the rear arb to be thinner than the front with the standard setup.

Have tried to google it but comes up with too many models and different markets

Many thanks.

P.S car is a UK spec 2005 widetrack sti.