30mm symbol tube manufactured by Tesla

The ZM1041S is a special character indicator tube with red coating for better contrast. The character height of 30mm makes this tube a companion to numerical indicators like the ZM1040. Its a rare tube, beause it was produced in less numbers as the numerical indicators. I assume these tubes were used in applications where positions are envolved (X-Y-Z axis) or in measurement instruments. According to tesla's datasheet a clear-glass editon, the ZM1043S, also exists.
Brand / Manfacturer Tesla
Same Types
Likely Tyes
Symbol height in mm 30
Characters / Symbols +,-,U,W,X,Y,Z
Decimal point none
Base / Socket B13B
Starting Voltage (typ) 170 V
Maintaining Voltage (typ) 140 V
Current per Segment 4.5mA
Reccomend Resistor 6.8kOhm = 4.5mA