6D3D (6Д3Д) is a vintage soviet signal (beacon) diode in a metal-glass envelope, which was used as a detector or monitor at ultra hight frequencies. Outer metal parts are silver plated. 6D3D is a direct replacement for the 2B22 diode, which is slightly different, but normally directly replaceable. All of the available pieces are new in box with original datasheet included (please look at the gallery pictures for more details). Year of production: 1963.