The GC10B is a Dekatron counting tube where the application of a pair of input pulses causes the neon discharge to move around the cathodes in the pin circle. The position of the glow is the readout. At the end of a revolution the tube generates an output pulse to drive another tube. The GC10B can accept pulses up to 4,000 per second.
The stacked ceramic discs hold the electrodes.
The central anode with cathodes and guides around the circumference of the outer circle.
The end window envelope is 29 mm in diameter, and excluding the IO base pins is 86 mm tall.