25th anniversary of the first nuclear chain reaction

50 £. - Portrait of Enrico Fermi and atomic pile - Orange Color - Stamp Perforation 14 ¼ × 14 b - Watermark stars IV - Intaglio printing - Printed from IPS Workshop cards values ​​- Sheets 40 - Size 30 × 40 (mm) - Mintage 18.000.000.