Radioactive thickness gauge, with Mullard MX168...
Radioactive thickness gauge, with Mullard MX168 Geiger-Mulle
Radioactive thickness gauge, with Mullard MX168 Geiger-Muller Tube, Griffin & George 903 ratemeter and 1 microcurie sealed source. In perspex case 510mm wide x 405mm high x 270mm deep