Can you ID the dealie?

[marty]

I have 2 skimmers, one of them had this thing in hole...
thanks

[youtube:2iirfr78]QGEYgsVA-lQ[/youtube:2iirfr78]

 

[UN1017]

That is a Vari-flo control insert. It is used to adjust skimming level and/or main drain suction.

 

[marty]

Edited to remove language filter circumvention. Please don't try to circumvent the filter. Bama

hot ****! so i in theory, if i were to remove, there would be 50-50 skimmer-main drain?
Im trying to find a suction side air leak, in either of lines.
So do i just slightly rotate vari flow while in hole?
THANKS!