6CG7 - 6FQ7 - 7026
The 6CG7, 6FQ7 and 7026 are equivalents & substitutes for each other. The versions with a center shield (also called 3 plate) are the most sought after because the shield cuts down on noise. These are interesting tubes and are electrically equivalent to the famous 6SN7, they just squeezed the tube down to fit in a small bottle.
These tubes do have the same pinout as the 6DJ8/6922/7308/6AQ8/6BQ7/6N1P and MAY work as substitutes in some amplifiers.