The 12SN7GT is a glass double medium-mu triode vacuum tube designed for use as a voltage amplifier, phase inverter, or oscillator in audio equipment, television receivers, and series heater-string circuits. Featuring an 8-pin Octal base layout and a 12.6V heater rating, it provides linear amplification with separate cathode connections for each triode section. Available in new old stock (NOS) and tested used conditions.