Russian 6P3S (6П3С) tetrode is used in output stages of low frequency amplifiers. It is russian equivalent of 6L6 tubes. It may be used instead of tubes 6L6, 6L6G, 6L6GA (another shape, bulb type) and 6L6GB. Maximum anode voltage is 400V, maximum voltage of the second grid is 300V. Tubes were measured with L3-3 tube tester. Will be delivered in original boxes. Boxes do wear some longer storage marks and there are also some pen/pencil marks from the stock countings. Tubes were produced in the 50's. Manufacturer: FOTON (Tashkent).