Select light level with slider, Switch on / off to selected light level. Large paddle switch to fit a standard designer wallplate opening. With HED technology dimming circuitry and low-end adjustment dial for compatibility with most high efficacy light bulbs. Power-failure memory. Voltage compensation. Mechanical air-gap switch to disconnect load power. UL Listed to control dimmable compact fluorescent (CFL) with integrated ballast and dimmable LED with integrated driver. 150 watt maximum dimmable CFL/LED. 120 volt, 60 Hz. Operating temperatures 0° C (32° F) to 40° C (104° F).UL Listed to US and Canadian safety standards.