The outer side of the upper leaf has a gilt brass nocturnal. The inner side of the upper leaf has a pin gnomon dial (pin missing) with common hours marked from 1 to 12, twice.The inner side of the lower leaf has a pierced lunar volvelle and a dial with folding brass gnomon for common hours marked from IIII to XII to VIII. In the spandrel spaces are the cardinal points named 'SEPTEMTRIO', 'ORIENS', 'MERIDIES', OCCIDENS'. At the bottom is the date '1529', corrected to '1539'. At the bottom centre is a compass (needle and ring missing) with card painted in red, blue and gold.
The outside of the lower leaf is blank.
See P. Gouk, The Ivory Sundials of Nuremberg 1500-1700 (Cambridge, 1988).
Ilaria Meliconi