The Type 38 is an audio output pentode designed for car radio use and operation on a 6.3 Volt DC supply.
The load should be 10,000 Ω and the power obtained is 2.5 Watts. The figures come from Thrower, the Cunningham data-sheet has different operating parameters.
The base cap has the resellers name of Crossley as well as the manufacturers name - The Ken-Rad Corp.
The top mica gripping the shouldered portion of the envelope. The control grid is connected to the top cap.
At this angle the three wire grids are visible as are the two hairpin filament loops.
The classic envelope is 38 mm in diameter, and excluding the base pins is 96 mm tall.
References: Data-sheet, & 1043. Type 38 was first introduced in 1936. See also1936 adverts.
