A closely matched pair of new old stock highly regarded Tungsol 5881 beam power pentode vacuum tubes. One tests 5025 uMhos/40.2 ma., the other 4958 uMhos, 40.4ma. with baseline acceptable of 3350 uMhos. Tested on Hickok AN/USM-118B tube tester.Tubes come in original boxes with one box with flap tears.