This Harmony XB4 plain lens push to test modular blue pilot light is supplied with 24V AC/DC, uses a universal LED. It has a metal bezel. Under normal conditions, the push-to-test pilot light is providing a best-in-class illumination to service your panel signalisation functions. During maintenance, one push on the head is enough to test the lamp and to confirm its good health. It is impact resistant, dust resistant, water resistant and vibration resistant thanks to its IP66 / IP67 / IP69 / IP69K, making it ideal for operation in harsh environments.