The polar finder ensures the quick and precise alignment of the mount to the celestial pole.
In order to do this, polar finders have a glass plate etched with the desired position of the pole star. By turning the mount through its right ascension and declination axes, the pole star can be lined up with this marker. To ensure that a mount can also be aligned in the southern hemisphere, many polar finders have similar markings for the southern sky.
When using an illuminated polar finder, the etched marker is always easy to recognize.
Unfortunately, polar finders are not standardised. The correct polar finder must be selected for a particular mount.