6L6 VINTAGE TUBES. QUAD. METAL. NOS? (3-RCA, 1-Ken Rad)

Description

This is a rare Quad of vintage 6L6 tubes. These were made for the U.S. military during World War II and the Korean war. They are in their original cartons as shown. These were tested on my B&K Dyna-Jet 707 tester with very strong readings of 82 to 88. I believe they are NOS based on test readings, appearance, and box. But I cannot prove that belief.
Due to their age (over 50 years!) I am only able to warrant that they match my description when you receive them.
I pack well and ship quickly within the contiguous USA.