Up for sale is a matched pair of Amperex USN-CEP 7308. These are the crème if the crop, as designated by the USN-CEP nomenclature. JAN tubes were selected tubes, destined for the military, for all branches. USN-CEP tubes were selected tubes, meant for critical applications, specifically for the navy. They were spec'ed the same as any other JAN Amperex 7308, except they had to have matched and balanced sections. Now whether this means they will sound better/different, well that is highly debatable .All sections on this pair are matched within 5% of emissions. Though these tubes test NOS, with regards to emissions, they are used. I think anyone looking for a premium tube, will be pleasantly pleased. All shipping is insured. Thanks for looking.