The 9006 miniature valve is a general purpose UHF diode and the electrodes are of the same order of size as an acorn valve.
This valve is new and came in a plain card package of outer wrap and inner sleeve. The outer card carries the date of 1944 and that it was accepted for the US Army and US Navy. The contractor supplying was Wells-Gardner & Co.
The side view of the anode.
The glass also has the Type designation etched into the glass.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 39 mm tall.
Reference: Datasheet. Type 9006 was first introduced in 1943.