This universal equinoctial dial consists of two separate parts, housed in a round leather case with slots for suspension. Impressed on the case are three sets of nine circles.
The base of the dial is a compass, engraved on the bottom with the names of 20 towns with their latitudes, in five rings divided in quadrants; 'CARTAGENA 38', 'CORDOVA 38', 'SIBILIA 38', 'LISABONA 39', 'TOLEDO 39', 'VALLADOLIT 40', 'SALAMANCA 40', 'BARSALONA 40', 'SARAGOSA 40', 'VALENZIA 40', 'PAMPLONA 41', 'NEAPOLIS 41', 'FLORENZIA 43', 'CONSTANTI<NOPOLIS> 43', 'ROMA 42', 'FVENTARABIA 44', 'MAILAND 45', 'TRENTO 45', 'VENEDIG 45', 'S. IACOB 44'. At the centre of the brass plate is an eight-leaf flower. On the extremes of a diametrical line are two bun feet shaped as flowers.
The compass needle has two brass spikes, perpendicular to the needle itself. The eight main cardinal points are named in German, and the eight main winds are engraved radially from the centre, in Latin. The signature 'CHRISTOPHORVS SCHISSLER FACIEBAT AVGVSTE VINDELICORVM' is engraved on the rim of the compass.
The second part of the dial is a circular disc pivoted on a supporting semicircle, which has legs for insertion into two holes in the base. A quadrant arm for setting the latitude is missing. One side of the disc is engraved as an equinoctial pin gnomon dial (the pin is detached but not missing), with hours divided to the half hour and numbered I to XII twice and 1 to 12 twice, clockwise and anticlockwise respectively. The top half of the disc is used during the summer and the bottom half during the winter.
The obverse of the disc is engraved on the limb with hour lines I to XII twice, divided to the half hour. The central part of the disc has a pierced rotating volvelle, showing the phases of the moon, and has an aperture and arm for the age and phase of the moon. It is also engraved with an aspectarium and has a small pin knob for turning the volvelle.
The instrument was bequeathed by Maurice Rosenheim in 1922 and is described in F. A. B. Ward, A Catalogue of European Scientific Instruments in the Department of Medieval and Later Antiquities of the British Museum (London, 1981), p. 47, no.120.