Ratios to 550ex slave unit?

[hawk911]

I'm trying to understand setting the ration on the slave unit when using 2 550ex models.

I can pick the 1:8 all the way to 8:1, but does that only control the master, or is it controlling the slave unit? I will beg forgiveness, as I should play but I'm trying to do 500 things before I sleep tonight.

TIA

Edit: I found this, and it answered/solved my problem. Thanks anyway

[Titus213]

Ratios control both units. One 550EX will be master (A) and the other slave (B) all controlled from the master.