This crude astrolabe has a small, tri-lobed throne and a blank mater. The rete's shape is based on Western Islamic models and it has 21 star pointers bearing the names of stars copied from an Eastern Islamic astrolabe. The standard of the five plates is poor, revealing the incompetence of the maker. On the back of the instrument, amongst various inaccurate tables and divisions, is the signature of the maker: 'hadha milk al-faqir Hasan 'Abd Allah' [This is the property of the poor (servant of God) Hasan 'Abd Allah]. The alidade has a linear sexagesimal scale on one side and two sights.