Sunlite 05597-su sl42/65k 42w spiral cfl light bulb, medium base, daylight sunlite high wattage spiral compact fluorescent lamps give off a daylight light much like a 150 watt incandescent bulb. These energy efficient cfl lamps can last up to 9.1 years with normal household use of 3 hours a day. This energy saving 42 watt 6500k, medium base bulb offers 2800 lumens of light output and has an average rated life of 12,000 hours.