MICRO 16, WHITTAKER, USA C-1947
Cast metal subminiature. B. Coe in his book ("Cameras") writes it was designed to fit a cigarette-pack. Was available in colors: chrome, green, black and blue (mine is green). uses FILM: 16 mm. in special cassettes. A single speed shutter with 3 positions: color, bright and dull.

Here how I created my own spy-camera with the micro16:
   
All you need is a full packet of cigarettes (I don't smoke so ...), cut holes for the viewfinder and the shutter, glue the edges of the filters to look like a full packet with cigarretes - insert the camera, cover it with the filters so the shutter-release stays in the same high as the dummy-cigarettes - and YOU HAVE - A COMPLETE OUTFIT!
I forgot to tell you - I couldn't find any film for the camera....