The design of the rete of this astrolabe includes a semi-quatrefoil, also called trefoil. Differing from the Hispano-Moorish style, instruments of this type were developed in medieval Europe from about 1260 until about 1360, when the 'Y' type of Gothic astrolabe became common.
On the inner side of the mater there is a roughly engraved coat-of-arms which has not been identified.
