Throttle Body question
 

What's that dime sized Slotted screw right above the throttle body intake mouth?

Air screw? Idle mixture screw? How many turns out from seated should it be?

I'm guessin 2.5 turns out from lightly seated???

year and type car would be helpful.....some intakes are different....is this one factory?

Found out what it is already. A manual from an Si says it's the idle adjustment screw. Thanks anyway though!