The Spartus 35F “Model 400” is a Bakelite 35mm viewfinder camera manufactured by the Herold Mfg Co (Not Inc) of Chicago. It features scale focus and a single speed shutter. Four apertures are available which are selected by an aperture dial below the lens. It appears to have been made between 1951 and 1960.
Mine was an inexpensive thrift store score. I’ve guessed the single shutter speed to be around 1/100 and loaded a roll of Fuji 200 ASA color.
REFERENCES:
Camera Wiki
Notes from Mosquito Hill 