Pulse modulator tetrode GMI-83 (ГМИ-83) from manufacturer Svetlana. Equivalent of the EV575 tube. Maximum anode dissipation is 65W. Maximum anode current: 15A. Max. height of the tube: 149,5 mm. Max. diameter: 65 mm. Weight of the whole box: about 450g. Tubes are new, unused and in original boxes. Manufactured in the 60's.