Philips 85-Watt 6 ft. T12 High Output Linear Fluorescent ALTO Tube Light Bulb, Daylight (6500K) (15-Pack)Brightness: 5600 lumens Estimated yearly energy cost: $10. 24 (Based on 3 hrs day, 11c kWh. cost depend on rates and use) Lasts up to 11 years (based on 3 hours day) Light appearance: 6500K (Daylight) Energy used: 85 Watts Lumens per watt: 65. 9 T12 bulb shape, RDC base Contains mercury: yes (for more info on cleanup and safe disposal, visit: epa. gov cfl) For indoor & outdoor, commercial and residential use Ideal for commercial use in high bay