6B4G, JAN, new old military graded stock by Sylvania in the USA, so low noise and reliable, supplied with original boxes
one pair, nice sounding tubes, they have rounded warm and detailed sound.
beautiful black plates, MATCHING DATE CODES, 2/1975 .
rare tubes in really super condition electrically matched
has green print on the black base
Had them carefully stored in my collection for over 20 years
Grab A bargain, Thanks For Looking.......