This is a PHILIPS ECG 12AX7WA long plate vacuum tube. PHILIPS ECG tubes are high-quality vintage vacuum tubes used in medical and precision equipment. The "WA" designation indicates they are resistant to vibration and have low noise. They were also used in guitar amplifiers and high-end audio EQs. This is being offered for sale to clear out inventory. I confirmed the sound output on an actual device before listing. Please take a look at the photos and consider it for your amplifier.