Two, new in box, RCA 5U4GB tubes. The 5U4GB can be used in all applications calling for the 5U4G, 5U4GA, and 5U4GB.  Black plates, with the upper silvering, red/orange printed logo base. Tested on a Hickok TV-3 military tester that has been calibrated, just to make sure. Firm bases, excellent silvering. Tubes test at 167-166 and 166-165 where pass/fail is 80. These are relative numbers and do not indicate percentages. Tubes have the same exact structure inside and out, having date codes of "AO" and "AE", April 1965 and June 1964.