Philips 100-Watt Equivalent T2 Spiral CFL Light Bulb Soft White (2700K) (4-Pack)Brightness: 1600 Lumens Estimated yearly energy cost: $2. 77 (based on 3 hours day, 11 kWh; cost depends on rates and use) Life: 11 years (based on 3 hours day) Light appearance: 2700K (soft white) Energy used: 23 Watt (equivalent to a standard 100 Watt incandescent light bulb) Lumens per watt: 69. 6 Uses 77% less energy compared to a standard incandescent light bulb Compact size can fit a variety of fixtures, including enclosed Contains mercury: yes