6sl7 tube nos Fivre Italy brown base 

2x tubes matched pair , same emission for each tube 

TV7 test results 

tube 1 = 50/48 (reference good at 32/32) code 110 

tube 2 = 50/48  (reference good at 32/32) code 110

both tubes identical inner structure, from the same lot , same factory code 110

brown base

fat plate 

smooth plate

square getter bottom

full mica on top

with own carton box 

with original military label on glass (selected tubes)

Old production 1950's 

Made in Italy 

original vintage vacuum tubes preamp 

pre amplifier tubes 

box 148