The 6K7G is a screened pentode and was designed for intermediate frequency amplifiers in superhet receivers. It is high impedance type allowing for a high Q in the tuned anode circuit.
See also6K7 metal envelope version and 6K7GT glass tubular type.
This is the same valve, Sylvania USA on one side of the base and Canadian Westinghouse on the other side.
The screening includes a top and bottom plate as well as the main cylindrical screen.
The classic envelope is 38 mm in diameter and, excluding the IO base pins the valve is 96 mm tall.
References: Data-sheet, 1040 & 1043. Type 6K7G was first introduced in 1936. See also1936 adverts.