20 pcs neon glow gas-discharge nixie indicator of voltage in form of cell DOT from military stocks of USSR.
It have a dark on the glass that mean its standart factory QC testing. 


Can connected directly to 220V, since have soldered resistor 110kOhm. For 110V must reduce resistance to 30-50kOhm

Direct current ignition voltage(without soldered resistor) - not more than 150 V.
The discharge maintenance voltage is from 80 V to 110 V.
Operating current - from 1 mA to 3 mA.
Ignition current - no more than 1 mA.
Power supply voltage:
- direct current - 160 V;
- alternating current - 120 V.

Diametr approx 8 mm
Length of tube approx 30 mm
Length of  pins(wires) 45 mm
Soldered Resistor - 110 kOm 
You can connect it directly to 220V power supply
Material glass, metal
Weight - approx 2g