Is the special valve tool a 5 mm /12 mm combination? I've seen in other posts that it may be a 6 mm. Which is it?

 

Here is the tool I am referring to: http://www.handsontools.com/Schley-89700-Subaru-12mm-Valve-Adjustment-Wrench_p_6518.html

 

It would be nice to get one of these if its the right size.

i woulda thought its a 5mm on the smaller one, ive got a 6mm spanner, and it seems a bit sloppy on there, dont have a 5 lol! i do mine the old fashioned way, seems alright but for the price and if your doing them maybe regularly, on a few cars, then probs worth it

yes, 5 and 12

 

after enough practice, it's easier without

use torque wrench to tighten lock nuts!!