‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari, ‘Astrolabe of ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari’, 1291, The Metropolitan Museum of Art

dated A.H. 690/ A.D. 1291; made in Yemen; case (a): max. W. 7 5/8 in. (19.4 cm), Diam. 6 1/8 in. (15.6 cm), D. 1/4 in. (0.6 cm); Bar with attached nail (b): max. H. 1 7/8 in. (4.8 cm), max. W. 1 1/8 in. (2.9 cm), L. 5 in. (12.7 cm); net (c): Diam. 5 in. (12.7 cm); plates (d-g): Diam. 5 in. (12.7 cm); pin (h): L. 1 3/4 in. (4.4 cm), W. 1/2 in. (1.3 cm)
http://www.metmuseum.org/art/collection/search/444408

Image rights: The Metropolitan Museum of Art (Edward C. Moore Collection, Bequest of Edward C. Moore, 1891), licensed under CC0 1.0 Universal