Features Cool temperature operation - Fluorescent lighting does not give off heat, which makes them safe for tabletop applications. Long lasting - Each bulb lasts 10,000 hours on average compare that to hot bulbs that lasts less than 750 hours. Flicker-free and rapid start - The bulb includes an advanced electronic ballast for smooth operation. Energy saving - Each bulb consumes only 30 watts but emit light equivalent to a 120 watt tungsten bulb. Unique bulb design - The patented design provides a greater center intensity than conventional fluorescent bulbs. Daylight-balanced - By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an overcast sky) are considered cool. Color temperature is measured in Kelvin (K) temperature. Cool light is preferred for visual tasks because it produces higher contrast than warm light. Warm light is preferred for living spaces because it is more flattering to skin tones and clothing.     Household lights with a color temperature of 2700-3600 K (left) is generally used for most indoor general and task lighting applications. Daylight color temperature lighting is preferred for product photography and the film industry because it provides the best contrast with primary colors.   1700 K Match flame 1850 K Candles 2800 K Tungsten lamps 3000 K Household light bulbs 3400 K Studio lamps, photofloods, etc... 4100 K Clear flash bulbs 5000 K Daylight 5500 K The sun at noon 6000 K Bright sunshine on clear day 6420 K Xenon arc lamp 7000 K Slight overcast day 11000 K Sunless blue skies