Electron tube 6P13S (6П13С) was used widely in TV receivers. It is a quality and direct replacement for chinese tubes 6P13P, which are recently used in amplifiers coming mostly from China (for example D-2008A-6P13P). Reliable tubes with gold-platinum grid. It is very similar to the EL36 tubes too, but it has another base (5-pin). Tubes were produced in Reflektor, Saratov plant in year 1979. New old stock and tested.