Pair of closely matched Western Electric 2C51/396A twin triode vacuum tubes-fully tested. One tube tests 5928/5776 uMhos, the other 5776/5928 uMhos with a baseline acceptable of 3800 uMhos. Could well be new old stock but no original boxes. Tested for quality prior to shipment on Hickok AN/USM-118B. Will come in white tube boxes.