Ella folding ophthalmologist scale, Ferdinand Monoyer test, used to test visual acuity, reading at 5 metres. Vintage, must date from the 60s/80s Very good condition, hard plastic, metal chain with minimal oxidation points, it can be hanged on the wall, folds into 3 parts. Dimensions: 55 cm high (62 cm with chain) and 24 cm wide. Shipping costs for France: €9, to Europe excluding Norway and Northern Africa: €16, and the rest of Europe: €20.