50mm numeric  tube manufactured by Unknown

This tubes manufacturer is unknown but the SZ-2 tube has a digit size of around 50mm in its relatively compact shape. This tubes seems to be very unique since no data can be found!
Brand / Manfacturer Unknown
Same Types
Likely Tyes
Symbol height in mm 50
Characters / Symbols 0-9
Decimal point none
Base / Socket 0
Starting Voltage (typ) tested at 170V V
Maintaining Voltage (typ) 0 V
Current per Segment 0mA
Reccomend Resistor tested at 10kOhm