IN14/CD81 Clocks Compared
Mouse over the image below... the CD81 Nixies are in the foreground.

IN14 Nixies.
Made in the the old soviet union (USSR).
Digit height=18mm. Tube Height=54.5mm including tip.
Russian quality! Note the 2 is an inverted 5, or visa versa!
IN14 Nixie Clock

CD81 Nixies.
Made in Japan by Hitachi (circa 1954).
Digit height=12mm. Tube Height=36mm including tip.
Japanese quality! Although the CD81 tubes are smaller, they are much sharper.
CD81 Nixie Clock

Sphere's Nixie Tube Page has a lot of nixie tube information and data.