They are real vintage gems, very rare triple mica version, no microphonics at all, with special cathode coating for 10000 hours of use within manufacturer's specifications.
One of the best ever ECC83 / 12AX7.
They are tested with 250V on plates and -1.5V on grids, 100% for NOS tube at these voltges is 2.15mA, the results are:
(1.9/1.8)
(1.7/1.7)
Nice SQ Long life pair with a lot of life left in some decent preamp.