This VT80 valve kit contains two JJ Elctronic ECC83’s (12AX7), and four 6L6GC’s. The 4 GC6l6GC;s and one of the ECC83S’s are hand selected and matched . A test certificate is issued with the Supermatch option. We test the valves on our suite of AVO testers. The valves have a 120 day warranty to ensure we cover the danger period when valves are most likely to fail for no apparent reason. They are old technology.