McVitie Weston valve collection, Tungsram valve, type DE4
Tungsram valve, type DE4, (RMW/E61 - McVitie Weston number), by Tungsram Electric Lamp Works (Gt. Britain) Ltd..
Tungsram valve, type DE4, (RMW/E61 - McVitie Weston number), by Tungsram Electric Lamp Works (Gt. Britain) Ltd..