Device for Measuring Inhibited Zones for Penicillin Extraction

Wooden box with one open side made up of five wooden blocks crudely nailed together. The box is lined with foil on four of the sides, the foil is labelled "British Manufacture". The top of the box is glass with a central scale inscribed with the measurements in millimetres, the scale is labelled "Carl Zeiss / Jena" in cursive script, around the edge of the glass the wood is covered with paper.