.....anywhere on the tube......not one?
I'll post a pic of the tube once I go get my camera.....but it has no markings at all.
It works great though.....so I'm keeping it....
The tube still has markings on the inside. - :)
Anyway your tube is probably a repot - and has most likely been assembled by a third party other than ITT or L3.
Not really an issue - if it works well, it's good :)