The ZM1020 is a medium sized end view Nixie tube with a red coating to improve contrast. This particular one was made by Telefunken. There are many tubes of a similar size that use the B13B base and are therefore plug-compatible.
| Digit size | 15.5mm |
| Min current | 1mA |
| Max current | 3mA |
| Base | B13B |
Datasheet:
ZM1020 Datasheet