This model was manufactured from 1966 to 1969.
This plastic-bodied monstrosity bears no resemblance to the earlier Retinas. The nicest thing I can say about it is that it is well-made.
The camera was fitted with a 45mm f/2.8 Reomar lens in a Kodak shutter, and can use flash cubes or electronic flash. This camera has a coupled selenium exposure meter, but no rangefinder.
Here is a link to a copy of the Retina S2 instruction manual on Mike Butkus' excellent website.