Fully Tested NOS NIB RFT / RSD Germany EF12 / EF12K Vacuum Tube

Fully Tested NOS NIB RFT / RSD Germany EF12 / EF12K Vacuum Tube

You don't see these every day! These are absolute beauties, branded RSD and made in Germany, our best guess is that these were made by RFT. This is an obscure tube but from what we can tell, only RFT used a lead shield which these have. I imagine these are quite similar to Telefunkens of the same era. 

 All of these have been professionally tested and/or matched by Gm on a calibrated Hickok TV-7 tube tester. These are genuine NOS tubes and they will test and perform as such.