The 6GE5 is a Compactron television valve designed as a power beam tetrode. The 6GE5 is designed to operate as a line timebase output valve with peak anode voltages of 5 kV and a maximum anode dissipation of 17.5 Watts.
Pro/Comm have probably rebadged a valve made by General Electric or RCA.
The Pro/Comm lettering is clearly an overprint. The original more permanent lettering and the USA can be seen on the left.
Looking along the grid axis, the side flanges are set where the maximum heat is generated. The anode is stitched together and would be thin nickel sheet.
Three quarter view showing the anode shape. The beam plate can be seen as a bright structure within the anode.
The electrodes are held in place by the mica discs. The rectangular cathode and tops of the inner grids are clearly seen.
The twelve pin base. Obviously an overkill for a single beam tetrode but other Compactrons could have three separate triodes in the same envelope shape and base.
The wide glass tube envelope is 38 mm in diameter, and excluding the base pins is 62 mm tall.
Reference: Data-sheet. Type 6GE5 was first introduced in 1961. See also1961 adverts.
