The IN-8 is the Nixie tube with a real “5”. Most Nixie clocks use the IN-14, which has no five and shows an upside-down “2” in its place. The IN-8 is the taller, older tube, and rarer than the IN-14. These clocks are made in small batches, and each one carries its tubes in sockets, so a tube can be changed by hand.
