Russian Gi-7B (ГИ-7Б) is a microwave triode with heat sink, that operates as an oscillator or an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges. GI-70B is the same tube, but without the heat sink. Tube is also physically identical to the GI-6B and GS-9B tubes, but there are some electrical differences. Tubes are new, never used and in original polystyrene boxes. Made in the the 70's.