521-9047 is a T-2 midget flange base neon lamp designed for indicator and signaling applications. It operates at 105–125 volts AC/DC with a current draw of 0.70 mA and an impedance of 100 kO, consuming 1/4 watt of power. The lamp delivers a rated lifespan of 25,000 hours, providing reliable long-term operation in control panels, instrumentation, and status indication circuits. Its compact T-2 form factor and flange base mounting make it suitable for space-constrained applications requiring low-power visual feedback.