Price is for one antique triode tube. This is made both in the US and in England which are marked (STC) Standard Telephone & Cables with patent numbers, etched serial number on glass sphere. Production estimated early 1930s or near. STC was founded in 1883 in London as International Western Electric by the Western Electric Company. The tube served Swedish telecom.
Tested VERY STRONG as follow:
Ia = 2.1 mA | S = 0.7 mA/V
Test under: Uf = 2.0V, Ua = 160V, Ug = -1.0V
Where 100% is Ia = 1.4mA
In case you are interested - I have some more of those in stock, although not matched.
Shipping will be Express Worldwide by DHL or UPS.