The FED Stereo has been manufactured in different versions by " Zavod Charkovskij Mashinostroitelnij FED" in Kharkov , Ukraine.

This is the chromium version of the FED Boy Stereo whose markings on the housing and lens are made in latin characters
FED Boy Stereo is the prestige export version of the FED Stereo M. But while the FED Stereo M has all inscriptions in Cyrillic , the FED Boy has all its writings ( housing and lenses) in latin characters.
Concerning the detailed specifications, the FED BOY Stereo and the FED Stereo M are the same improved versions of the FED Stereo Standard . However, if the design is similar to the latter , the realization is improved and models  are more reliable.

Both versions , FED stereo M and FED Boy, were available in chromium or black versions .

See the description of the FED Stereo Standard for the operation and main characteristics .

Functional differences with the FED Stereo Standard are mostly practical.

On the FED Stereo Standard, the salient sensitivity adjustment knob could be easily turned accidentally. With the FED Boy, this is no longer possible. Sensitivity settings are ranging from 16 to 800 Asa , with a neutral position shielding the cell and saving in theory some power supply from  the battery.
 

The FED Stereo Boy has, located on the left lens, a notched distance adjustment ring with positioning clicks. A system that was not available on the FED Stereo Standard .
Manual selector at the right lens provides choice only for 5 diaphragms, 2.8 to 11 for use of a flash.
The bulb exposure is now made with the aperture 5.6.
Finally, the power is supplied by a SR44 silver oxide, 1.5 volt battery. The battery compartment door has an adapter ring made ??of plastic. There is still no possibility to turn off the power , it is therefore necessary to remove the battery in case the camera is not used during a long period of time.