Front dial and 7 days of the week with selection knob

Back dial. Displays sun and moon in the zodiac, phase of the moon and age of moon in days

Location latitude is selected and gnomon is turned to appropriate month to use sundial

The days of the week knob is turned daily to operate the gear train that rotates the back displays

Sun in the zodiac display

Moon in the zodiac display

This pointer on the hanger mechanism, sets the latitude of your location

Astrolabe