the CF GU24 base bulb is a Coil Twist and Lock dimmable compact fluorescent lamp. 82 CRI. 2700K. 18 or 23 watt, 120 volt. 2011 Platinum ADEX Award winner. Continuous smooth dimming down to 10% lumen output. Integrated Circuit technology provides longer life when dimming compared to other CFLs. Fits standardized line voltage socket promoted by Energy Star. Ideal for residential and commercial applications. Average lamp life 10,000 hours.