In the 1930s and 1940s the name Luminor identified the luminescent substance that was used by Panerai to increase visibility underwater. Over the years the term Luminor have come to identify the type of case. The Luminor case was in fact born out of the need to make the Radiomir case even more resistant and watertight. This is why the crown-protecting device was added, shielding the crown and making it more watertight.  The Luminor 1950 case represents another stage in the evolution of Panerai cases. The case-middle of the Luminor 1950 3 Days is rounded and cusp-shaped on the sides, a direct development of the cushion-shape case which still characterises Radiomir watches today. Supplied triple boxed with the instruction manual, certificates booklet, additional brown leather strap, barcodes, strap change screwdriver and spare glass.