The Ultra Sun 901528 400 watt high pressure sodium grow lamp is designed to rival bulbs three times the price. Its digital technology is engineered to operate with modern horticulture equipment and maximize output and longevity. A ceramic insulation plate, a stainless steel armature, and a newly designed proprietary starter allow this lamp to withstand the acoustic resonance and harmonic distortion of high frequency electronic ballasts. At 2000K, this HPS lamp creates 50,000 lumens of light within the red spectrum, making it perfect for the fruiting and flowering stages of your plants. Its 24,000-hour life is backed by 1-year warranty, so try it for yourself!