The box is 36 mm square and 86 mm long.
Here is a standard RCA two part box that has been overprinted with US Navy, US Army and has Order No. 4557 Phila-43 and was accepted inFebruary 1944. The Type designation for the US services of VT-211 is also printed on the box. This valve was exported to the Uk where it was distributed by Brimar.