Got the adj vac adv today.
Quality leaves a lot to be desired. I spent about 20 min trying to get the allen wrench to engage the internal hex. Finally I tweeked the mounting bracket and gently forced the allen wrench into the socket. The internal guts seemed to be loose in that turning the allen wrench ccw as instructed only met with limited resistance then a "click." I wiggled the actuator rod a little and the internal guts seemed to take a seat.
From here I can adjust it as per the instructions. Sure hope this thing stays adjusted as it will be very difficult to reach once installed.
Made in the USA I think.