The EBC91 double diode triode is the standard design for this B7G implementation of the last in the Magic Three superhet valve line-up.
The EBC91 is an improved version of the EBC90 which is more commonly known as the 6AT6. The distinctive features are the central triode section with two vertical anodes made in an n shape with the active area at the top of the common cathode.
The central dark triode anode with the two diode anodes seen edge on. The vertical rod on the right is connected to the cathode and a screen above the top mica.
The screen support connects to the base pin with the cathode connection as a tape spot welded two thirds along the screen support below the lower mica.
Here the separation of the two diode anodes can be easily seen.
The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins is 48 mm tall.