Some of the rarest 6SN7GT vintage tubes are shown in this video. Mostly 1940-1965 military types, the VT-231, 6SN7W, 6SN7WGT, and the super-rare 6SN7GT Tung Sol round plate blackglass types are shown. Internal construction details are shown, along with label markings and various getter flashings of these most desired NOS 6SN7 types.