The wing set screw threads horizontally through the wing mounting block and, with the wing thumb screw, hold the wing mounting bar in compression. The set screws can both be moved in or out to make fine adjustments to the wing's position in the boat, or individually to make very limited adjustments to the wing's perpendicularity. Blue Loctite should be used on the set screws to ensure that once an adjustment is made, the screws do not back out from repeated loading.