Topcon’s quality matched the requirement of the US Navy. For several years Topcon supplied the US navy with SRL bodies, lenses and motordrives. The US Navy lenses had an red colored N engraved and most of them wil have a a small metal lever for focus adjustment (all weather circumstances usage). In total 3 camera models are to be with US Navy engraving found on the bottom plate: the Re Super/Besseler D, the Topcon Super D and Topcon Super DM, the later with normal pentaprism finder.
Some body will have specific modifications made to them. Lenses were provided form both the Re-auto Topcor series (most common: 58mm, 35mm and 100mm) and the new Re series (135mm), also a zoom lens was provided. The durability of the Topcon camera proved itself with this navy series, where even nowadays the heavy used and “misused” bodies are mostly all fully functional operating.