British made English Electic Valve C1166 CV10404 output tubes. They are all new in the original military packaging and show no signs of ever being used. The price is PER TUBE. Limited quantities available. This item is shipped from Britain, in North America or Asia please allow 2 to 3 weeks for delivery.
Here is the spec sheet for this part: http://tubezone.net/pdf/c1166-eev.pdf Apparently they are similar to and interchange with Eimac 4PR60 ( has same socket and filament voltage) please refer to data for the two tubes for more details.