The SOK II was replaced by the SOK III.
They lock just like the big awnings - there is a hole for a pin that goes through the inner tube. A 1/4-20 bolt also works - thread it into the hole and tighten it against the inner tube. Doesn't take much, so don't torque hard and strip the bolt in the aluminum frame. There is a hole on either end, but the one that needs to be locked (where the torsion spring is) is the left side as you look at the side of the coach. The other end is just a free-turning spindle, so no hole through it and no reason to lock in place anyway.
2004 American Tradition; 2013 Buick Verano
Homebase in the Ocala Nat'l Forest near Ocala, FL