The W-Nikkor.C 1:2.5 f=3.5cm uses a 6 elements 4 group optical design. There is no known MIOJ engraving nor f/16 version existed. The early design has similar nature with its predecessor in few aspects, which including the aperture control method. Using chrome with brass mount, it is a solidly built wideangle lens but the most appealing factor is its improved, faster maximum aperture with reasonably high definition which opens up wider acceptance as well as extending broader range of available light photography.
The Nikon S-mount is a type of interchangeable lens mount used by a series of Nikon 35mm rangefinder cameras (Nikon I, Nikon M, Nikon S, Nikon S2, Nikon SP, Nikon S3, Nikon S4). The lenses were sold under the name Nikkor.
This is a USED lens there are some scratches on the coating but it doesn't seem to show on photos. The lens looks clean and clear with no haze, fungus, spots, ETC. It does have slight dust like all lenses this age.