The CV1739 is a bi-directional cold cathode 10-way counting & display tube. The commercial Type designation is GC10/4B.
In use the discharge would cause one of the cathodes to glow and its position would indicate a number. The cathodes and guide electrodes are all arranged around a central common anode. The orange glow of the neon discharge allows the position of the discharge to be seen and thus functions as a indicator. An output pulse is achieved once for every ten input pulses allowing cascaded devices to form the digits of a decade counter.
The GC10/4B on the glass in the same ink as the CV reference. The electrodes are all mounted between ceramic discs. The central tube shields the anode connection.
The central anode with cathodes and guides set in a ring around the circumference.
The standard IO base.
The end window envelope is 29 mm in diameter, and excluding the IO base pins, is 84 mm tall.