This small astrolabe carries four tympanums for latitudes 24°/30°, 31°/35°, and 32°/36° (corresponding to Persia), and for latitude 0° (i.e., the circle of the equator) and 66°. There is an alidade and a rete. The back of the mater displays a lunar calendar, in accordance with Islamic use, a shadow square, and a quadrant. The instrument is dated 496 of the Hegira (1102-1103 of the Christian era) and is signed by its maker, Muhammad 'Ibn Abi'l Qasim 'Ibn Bakran, on whom we have no information. Donated to the Museo di Storia della Scienza by the Florentine Prince Tommaso Corsini.