The RG12D60 is a German full wave rectifier and designed for military equipment and features a 12.6 Volt heater for mobile equipment. The rectified current is 60 mA maximum and the reservoir capacitor has a maximum value of 32μF.
The maker is TeKaDe or TKD and the valve is marked Wehrmacht Eigentum. So this was the property of the Wehrmacht or German unified armed forces.
The two anodes are mounted in X formation one above the other on the common cathode. The lower anode has the fins pointing up and the top anode has the fins pointing down. Together they offer the greatest radiating area.
The top anode.
The six pin base. The central brass thread is present to allow the fixing of a knob for rapid replacement in the field.
The thin glass tube envelope is 20 mm in diameter, and including the De6 base pins is 58 mm tall.
Reference: Datasheet. Type RG12D60 was first introduced in 1940.