Calling Genelec sub users

wave100

I just acquired a 7040A off of Gumtree - there is a Roll-off control on the sub to offset the level it produces, but I am unable to adjust it as the plastic of the "knob" just distorts when I attempt to use a flat blade screwdriver or a pair of needle-nose pliers on it. Is there a special tool which I need, or is there some other way of adjusting it without destroying it?

Thanks in advance.

wave100

Update - issue resolved, pilot error the cause:- I had foolishly thought that the calibration labels on the device actually referred to something meaningful but the reason I couldn't turn the "knob" was that it was turned all the way up and I was attempting to move it in the wrong direction, as an "offset" it goes in a counter intuitive direction!
Anyway, sub level now sorted and it's sounding awesome!