Of rectangular brass plate on four riveted feet, with inset compass-box, engraved hour lines, place names, cardinal directions, meridian line, with signature in cartouche.
6.8 by 9.8 cm.

Signed as: sana'ahu 'abd al-aimmah, 'Made by 'Abd al- Aimmah'
The upper face carries the hour lines for a horizontal dial counting from sunrise to sunset (Babylonian hours) numbered 1-14 in abjad numerals and with 30-minute divisions ending in trefoil leaves. Time is read from the tip of the shadow of a hinged pin-gnomon set on the meridian line beneath the compass-box. A degree arc in the top right corner is divided by 1° divisions 0-90° with every five degrees numbered in abjad. A narrow leaf-shaped pointer can be set against this scale to mark the inhirâf of a particular place, the value being derived from the table of thirty-eight named places, with their inhirâf, engraved along the edges of the instrument. The four cardinal directions are named, as is the meridian line. The compass retains its original needle in the form of a bird, characteristic of late Safavid and succeeding Persian instruments.

The layout and script of this instrument, although not identical, resemble very closely those on another instrument signed by 'Abd al-Aimma, fl. 1115 -1132 AH (1703/4-1719/20 AD), see Dominique & Eric Delalande, Cadrans solaires, Paris 2013, p.384, no.21.