The MOD-SIX_7971 is a true direct drive 6 digit Nixie clock designed specifically for the very large Burroughs 7971 segmented Nixie tube . This clock is unique, both in appearance and function!! It is the only B7971 Nixie clock I know of that incorporates the following: auto brightness control, single rotary encoder user interface,  extensive font catalogue, QUIKSET time-set feature, Maxim DS3232 RTC time accuracy, tube life timer, built in segment test function, and much more... all of which make this Nixie clock a true classic. And even though it offers the convenience of GPS time sync, it is NOT GPS dependent. So if you live in an area with poor GPS reception it will still maintain extremely accurate time. Carl Ott of New York designs the electronics and writes the software and I chip in with case design, aesthetics, and ‘marketing’. Click here to see the MOD-SIX video on YouTube.