0 to 10 V 3-Way Dimmer Switch with 500 W rated power, 120 V rated voltage, 20/000 times (one reciprocating time for each switch) mechanical life, neutral and live wire power supply. For indoor applications. Power supply design: isolated power supply design, can be used with dimming power supply. LED dimming indicator: 5 LED dimming progress indicators, through the indicator can visually view the dimming brightness percentage. Zero crossing detection: The product supports zero crossing detection circuit to extend the service life of the product.