The Radar Sentry enjoys it's prestigious place in history as (for all practical purposes), the first commercial radar detector! A LOT more history and data on the Radar Sentry can be found on the Radar Sentry on our page about The First Commercial Radar Detectors.
This particular Radar Sentry is probably the oldest detector in the whole Radar Detector Museum. It was likely manufactured sometime between August 3rd, 1962 (when Radatron applied for a patent on the unit), and June 18, 1963 when the patent was granted.
Note the "patent pending" at the bottom of the face.
The antenna is "flat" instead of angled like most later Radar Sentrys..
Note the lack of a patent number at the bottom of the back..