The instrument consists of a box with a suspension ring and a hinged lid. There is a broken clasp.
The upper face of the cover leaf has an engraved coat of arms in a decorative border along with the initial's of (presumably) the first owner 'H P' and the date 1589. The sides of the lid carry hatched decorative engraving.
The inside face of the cover contains a circular scale 1 to 12 within an engraved wreath. There may once have been a rotating index fixed at the centre of the scale. Along the outermost edge is the signature 'ANDREA . MAR . FECET'.
The main box carries a horizontal string-gnomon sundial. There is a decorated folding gnomon support incorporating a plummet and sprung to the vertical. The scale of hours runs from 4 to 12 to 8 and the string emerges from the centre of a sun figure. The inset compass is 19 mm in diameter with a cross of direction labelled 'S', 'OR', 'M' and 'OC' and is marked for variation.
The sides and base of the instrument carry decorative engraving.
Provenance: Lewis Evans Collection G. 398.