This is an Polaroid-based oscilloscope camera, intended to take pictures of the data on a CRT oscilloscope. Modern digital oscilloscopes typically have a screenshot function, rendering a camera like this obsolete. This particular model can be directly mounted to a Tektronix 577, 600-series, 1420-series, or a 5100-series instrument. It has a fixed focus and aperture, and a small viewing window so that the user can view the oscilloscope readout while using the camera. This model has serial number B049465.