Proprietary, exclusive OttLite ClearSun® LED, reduces eyestrain by 51%. Provides smooth, uniform light with Color Rendering Index (CRI) of 97. Three color temperature modes. Memory feature remembers your last setting for color temp. Three brightness settings with touch controls. Maximum lumen output of 420. Super flexible neck holds position to direct light right where you need it Metal design features large dome shade and two-tone look and includes 5V, 2.1A USB port to fully charge smart phones and tablets. Height adjusts from 3' to 22' and base diameter is 6'. Energy efficient LEDs rated to last up to 40,000 hours.