Pair RCA 6L6GC black plate early 1960s, good tested in old boxes. All original, used RCA 6L6GC tubes - tested, current matched and working well; guaranteed no DOA. They test strong- and are in very good used condition… perfectly matched for plate current and trans conductance on multiple testers including AT1000 at real world voltages. They were also played … sounding great .. as original RCA 6l6GC's always do … they seemed strong and quiet, no gas or shorts, no microphonics at all. 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! (some wear and age, foxing and marks on old boxes). Really nice for collecting or using right now in your amp! They are the early ones ... 6 hole black plate , copper pipe, single side getter version of the 6L6GC -  the real McCoy!  Studying 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. Probably one of the best & most throughly checked over pairs anywhere online… they will sell quickly. And nearly perfectly matched ip & mhos -- you don't see that very often. Buy Now to avoid a bidder’s war. Fast shipping, see feedback on tubes, 100% happy customers.