The XN-13 numicator from Hivac is a regular size nixie tube. It features the gold-colored anode that is common to Hivac tubes. To my eyes, this seems to be a chromate conversion coating.
| Digit size | 15.5mm |
| Min current(guess) | 1.5mA |
| Max current (guess) | 3.5mA |
Here are some photographs of the tube from various angles, followed by a video of it in action. Some additional information is at the end.
Compatible tubes: GN-13A