FLUSH is having the top of the needle (where you put your screw driver in) turned out far enough that it is the same height as the top of the brass tube it sits in. If you run your fingernail or screwdriver across the top of the needle you should not feel the edge of the brass lip - ie the needle should be "flush" with the lip. Hope that explains it for you. Let us know how that 7 Port goes with these settings. It should be sweet