The EZ80/6V4 is a small full wave rectifier. Zaerix re-branded valves from Eastern Europe and their origins were rarely known. This valve is different as the glass carries the origin as the GDR. GDR was the German Democratic Republic - the communist East Germany.
The construction is typical with two anodes mounted vertically on a common cathode.
The heater hairpin is single strand insulated wire.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 57 mm tall.
References: Data-sheet & 1040. Type EZ80 was first introduced in 1954.