Two new old stock General Electric 5963 vacuum tubes in original boxes. One date code 6226, one 6252. Nice closely matched dual sections. One tube tests 3384 uMhos and 3456 uMhos per section, other tube tests 3312 and 3384 uMhos. Tested on Hickok AN/USM-118B tube tester with minimum acceptable test of 1800 uMhos. Quality replacement for 12AU7 vacuum tubes.