This unused, old stock 12AX7 is a high gain preamp tube with ultra low noise. Its European equivalent is the ECC83 and it can also be used in place of the 7025 found in Fender amps. It provides a detailed tone that rivals the most desirable US NOS types. Unique spiral filament eliminates the filament-to-cathode induced hum common on AC powered amps. These tubes are OEM which means they were intended for installation in new production amplifiers and therefore have no label. They are the exact same great tube as the labeled version but at a lower cost.