This vintage Sears Roebuck subminiature camera, the Tower 16 uses special cassettes for up to 20 exposures on 16mm film. The image size is 10 x 14 mm. The lens is a 25mm f/3.5 with aperture adjustable to f/11. The shutter is synchronized for flash and adjustable from 1/2 to 1/200 second plus bulb. The viewfinder is a simple metal frame that retracts into the body when not in use. The camera focuses as close as 1 foot or. There is no rangefinder however, so distance needs to be measured or estimated. The lack of a rangefinder is not a big drawback because the lens has a large depth of field. Only close distances require measurement. An interesting detail of the viewfinder is a parallax mark at the 1 foot distance. If you have one of these cameras, and you have wound the advance wheel, but the shutter does not fire, pull out the viewfinder frame. The shutter is locked when the viewfinder is retracted to prevent accidental exposures when carrying the camera. One other nice feature of this camera – notice a circular cutout below the triangular Tower logo engraving on the top cover. Inside the cutout are radiating black and white lines. When the film is advanced, the lines spin to indicate that the film is advancing properly. This camera comes with its original zippered leather case.