Ge Lighting 63509 Reveal Bright From The Start A21 Cfl Bulb, 20w A21 shape with medium base for use in table lamps and enclosed fixtures Lasts 7.3 years based on 3 hours per day usage Estimated yearly energy costs $2.41 based on 3 hours per day $0.11 per kWh $48 in energy savings over the life of the bulb based on 3 hours per day usage Lamp type: Compact Fluorescent, Self-Ballasted