[Amps] National Power Tube

[robert briggs]

Hi all.This is just a curiosity question.
I picked up a box of radio junk the other week with a few tubes among other sundry things.There were a few new TT21 and KT66 tubes and some old 866 mercury vapor tubes.
The tube I am curious about though is a National Power Tube type NL-7786-Ne.It also has 2604 in red branded on the base shell..I Cannot google any info on it.Thought it would look good mounted as a shack talking piece.It has an anode top cap and four very heavy connectors on the base.looks like some kind of large regulator bottle.
73 all....Bob VK3ZL..