2 tubes 50l6gt NOS Fivre made in Italy 

same code F8K 

with own original vintage carton box

tested strong & matched pair test results on Hickok TV7D/U 

test results = 88 & 88 (reference good at 45) same emission for each tube

reference 100% = 70

same inner structure

square getter

coated glass

rare tubes in such version old production from 1950's 

gold era of vintage audio tubes 

great power tubes for Coffman Labs headphone amp

box 199