McVitie Weston valve collection, STC valve, type 4050BBX
STC valve, type 4050BBX, 7in diam screen, length 1ft 6in overall, (RMW/K26A - McVitie Weston number), by Standard Telephones and Cables Limited.
STC valve, type 4050BBX, 7in diam screen, length 1ft 6in overall, (RMW/K26A - McVitie Weston number), by Standard Telephones and Cables Limited.