The stamped inscriptions on this ivory dial are filled with red, brown and black colour. It is decorated with geometrical patterns. The wire with which the two leafs were once attached to each other is now missing. Two clasps allow the dial to be closed, one clasp on the opposite side holds it open while in use.
The outer surface of the upper leaf contains a volvelle for converting lunar time into solar time. It consists of two circles and a movable brass plate with an index. The outer circle gives the age of the moon 1 to 29, numbered by 1, the inner circle a 24-hour scale, numbered anticlockwise twice 1 to 12. The brass volvelle also has a 24-hour scale, numbered anticlockwise twice from 1 to 12. A circular aperture in this volvelle allows the phases of the moon to be seen.
The volvelle is surrounded by a windrose with the cardinal directions marked on the outside where east and west are given as 'ORTUS' and 'OCCASUS'. The windrose has 32 directions in German mostly abbreviated. A hole in the northern side of the windrose allows the compass needle set into the lower leaf to be seen.
The dial is laid out for different latitudes, two of which are 51? and 48?. Two texts on the outer surface of the upper leaf explain to which localities these latitudes correspond: 'DAS L[Olunar]CHLEIN 51 BRAUCHT MAN IM NIDERLAND POLEN PREYSSEN POSSEN PEHEM SACHSSEN HESSEN MEICHEN TRESSEN'. 'DAS L[Olunar]CHLEIN 48 BRAVCHT MAN IM TEVTSCHLAND [Olunar]STERREICH VNGERLAND BVRGVNDIA BRITANIA'.
These explanations are continued on the inner surface of the upper leaf for the latitudes 45? and 42?: 'DAS L[Olunar]CHLEIN 45 BRAVCHT MA<N> IM WELSCHLAND VENETIA LEON FRANCKREICH GENFF LOTHRING SOFFEYERLA VERONA BONONIA GENVA NARBON MAYLAND PADVA ASTA MEDIOB PAVIA XANTONA MANTVA LOSAN'. 'DAS L[Olunar]CHLEIN 42 BRAVCHT MAN IM ITALIA FLORENTIA ROMA SICILIEN NEAPOLIS TVRCKEY CONSTONTINOPEL HISPAN<IA> LYSIBONA PORTVGAL AFFRICA CVSICA PERVSIA CORSICA CASTILIA'.
On the top is a pin gnomon dial with the names of the months in Latin and the zodiacal symbols but without hour lines. The pin is set into a sun effigy.
There are holes for the attachment of a now missing string gnomon for latitudes ('G') 42?, 45?, 48?, 51? and 54?.
The inner surface of the lower leaf contains a large string gnomon dial and a pin gnomon scaphe dial.
The string gnomon dial has five circles with hour markings 1 to 12 to 8 for the latitudes ('POLVS') 42?, 45?, 48?, 51? and 54?. At the top left and right hand corners is a picture of a blowing face. Inset in the centre of the five circles is a compass with the cardinal points marked and a magnetic deviation of 25? W. The compass needle is now loose and the glass appears to be a later replacement.
The pin gnomon dial is marked for Italian hours from 8 to 24 (in red), inscribed 'STVND DES AVFGANGS' and with the lengths of the days in hours (in brown) from 8 to 16, inscribed 'DES TAGS SEIN LENG'. The tropics are marked and the equinox is given as 'LIBRA'. The lower part of the scaphe is decorated with a stylized flower.
Left and right of the scaphe is the signature of the maker 'hans ducher zu nurnberg' and his mark, a vertical serpent with a crown.
The outer surface of the lower leaf has the date '1581' with the maker's mark stamped twice between the 5 and the 8.
In a band around the outside is further information on the latitudes: ' DAS L[Olunar]CHLEIN 54 GRAD BRAVCHT MAN IN ENGELAND SCHOTLAND WILDAW MOSCOWITERLAND SCHWETIN SEELAND LIFLAND DENEMARCK VND IN SEESTET<EN>'.
The instrument was presented by A.W. Franks in 1871 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. 37 ff., no. 84.