Electron tube 6F6M1 (6Ф6M1) is a pentode, which was designed for usage in output stages of low-frequency amplifiers. This is the metal base version of the 6F6M1 tube, which is nowadays becoming quite scarce. It is direct replacement for the soviet 6F6S (6Ф6C), 6F6M (6Ф6М) american 6F6G, 6F6 (DDR) but also for the VT66-A and CV1911 tubes, the only difference is in the shape of the bulb. New old stock and tested. Years of production: 1953-1954. Made in the well known NEVZ, Novosibirsk factory.