Two (2) tubes, matched pair within 5% of rare E88CC 6922 Tesla made in Rozhnov tube plant in Czechoslovakia in 60s.
NOS - New Old Stock
NIB - New In Box
Gold pins, perfectly matched, the same date codes, from 100 pcs service box.
They are tested on calibrated Tesla BM215M tester for plate current and tested for hum and noise in preamplifier.