For sale is one (1 pcs) used, tested E80F tube, pullout form professional devices. Heerlen codes, made back in 60s, big ring getter. These are real long life tubes with advanced cathode coating, made to last more than 10000 hours. SQ - Special Quality, when it wasn't just marketing ploy, like today. EF86 / 6267 eqivalent.
As is, some have good printings, some do not have.
Tested for anode current, not tested for hum and microphonics!