MATCHED QUAD of 1965 and 1966 close produciton RCA 6L6GC 6 hole black plate, single side getters. Strong and current matched (balanced) in the original RCA boxes. All original vintage tubes, lightly used very low hours or none at all, from early HiFi equipment estate, 40 years in storage. Just throughly tested in multiple testers and played with music. Working well; quiet and matched, detailed and sounding great! Guaranteed no DOA. Most throughly tested, closest matching set you will see anywhere...they will sell quickly. Dealers everywhere can no longer find these early ones, as haven't been made for nearly 50 years. This QUAD: plates are incrediblely close in Current (iP & transconductance .... they are all very close production .. dating from the mid 1960's (see tags). Cosmetics are also near mint, like NOS.... a couple of tubes have a tiny mark from clamp many years ago (you can't even see under bright inspection lamp. Strong and quiet, no gas or shorts, no microphonics at all. They were carefully checked and played with music -- for full details please read the reports in photos below, for date codes and test results. These are really cool and have original 50 year old RCA boxes included! ( almost 50 years old as they are very old boxes -- so they have a little foxing). Again, these are they are the early version of the RCA 6l6GC ... 6 hole black plate ,single side getter, horshoe top -- the real McCoy! Study the included tube test results in photos. If you're currently a user of modern tubes then these will make a world of difference in your sound — a real upgrade and a treat for your ears -- clean, clear and more overall detail you can really hear. This QUAD is the best you'll see on here & most throughly checked and CLOSELY matching ... so to repeat, they will sell quickly. And with nearly perfectly matched ip & mhos -- you just don't see that very often. Buy Now to avoid a bidder’s war. Check my 100% feedback...always fast shipping, and always safe double box packing !! 100% happy customers on all tubes and old audio items.