Phillips 429480 A19 60-Watt Medium Base Incandescent E26 120 Volt Agro-Lite Indoor Light Bulb for Plants LIFE EXPECTANCY: 11 months (based off of 3 hours per day of use) ACCELERATE YOUR PLANT GROWTH: This bulb is designed to be used indoors to act as artificial sunlight to boost the growth of plants FULL SPECTRUM LIGHT: These bulbs provide a full spectrum of light. Exposure to this type of light helps improve mood. PORTABLE: These bulbs are ideal for use in portable lighting fixtures LOW ENERGY COST: These bulbs will cost you an estimated $7.23 per year on electricity