This unused, old stock Electro Harmonix 12AX7 is a high quality preamp tube also known as ECC83. It provides high gain with ultra low noise and detailed, musical tone that rivals the most desirable US NOS types. Unique spiral filament eliminates that filament-to-cathode induced hum common on AC-powered amps. Ships in generic box. Date codes will vary. Approximately 2008 vintage.