Iron quadrant with lines, numbers, and digits inlaid in gold and silver. The front carries a curved cursor with the zodiacal band and the signature of the maker, Johannes Giamin (OPUS. IOANIS. GIAMIN. GALLI. BURDEGALLENSIS. ROMAE). On the back is the index arm and an astrolabe quadrant modeled on Oronce Finé's design. Provenance: Medici collections.