Osram Catkin valve, type VMS4, copper-glass envelope, top cap and 5-pin base, no external screen, (RMW/G68A - McVitie Weston number), by Osram, 1933.
Osram Catkin valve, type VMS4, copper-glass envelope, top cap and 5-pin base, no external screen, (RMW/G68A - McVitie Weston number), by Osram, 1933.