Tablet of coniferous wood with vein very marked and spaced (larch?), marked with a metal tip at the center for the whole length of a central line that is the center for nine series of circles and semi-circles of variable diameter
recto: (label printing) Antonius Stradivarius, then five handwritten letters to the edge of the tablet "P.G.P.M.S." / verso: five letters arranged around "M.P.S.G.G.".
