How do the positioning screws work on the Temp-Vent foundation vents?

The four positioning screws on the Temp-Vent foundation vents are for centering and squaring the vents.

The four screws are for centering and squaring the vents. Two clips are inserted in slots on top, and two on the bottom. When the vent is installed in the opening, the pressure from the springs pushing up and down on the bricks actually does the holding. The screws are then used to center the vent and make sure it is squarely in the opening.