This is a very unusual astrolabe, and not only because it is very small. The limit of the projection is the equator, whereas it is usual for it to extend to the Tropic of Capricorn. Thus the ecliptic is only an arc that has to serve, by symmetry, for the whole year, instead of being represented as a full circle.
The engraved plate beneath the rete serves for a single latitude of about 38?.
This is one of the most modest astrolabes yet one of the most significant in the Oxford collection.