This page shows the different variations of the Pozycja zamknięta from an Icons8 icon pack. Feel free to resize and recolor the icon, and then download the icon in PNG format for free. Icons are available in PNG and vector.
The Close Position icon is a small X with a square surrounding it. There is a black line jutting out from the lower left corner of the square. This line is crossing a horizontal dotted line where the horizon would be.