Check the listing for details. PREMIUM QUALITY SELF BALLASTED METAL HALIDE LAMP 250W E40 5000K HYDROPONICS. Condition: New. Listed at 18.78 USD. THIS LISTING IS FOR ONE PREMIUM QUALITY BRANDED HIGH OUTPUT SELF BALLASTED METAL HALIDE TUBULAR LAMP250W OUTPUT5000K DAYLIGHT COLOUR OUTPUTE40 BASE (40MM SCREW TYPE)220V-240VLENGTH 255MMWIDTH 48MM12000 LUMENS OUTPUT THESE LAMPS ARE SELF BALLASTED AND ALL CONTROL GEAR IS CONTAINED WITHIN THE LAMP. THESE CAN BE CONNECTED DIRECTLY TO A 220-240V SUPPLY USING AN E40 CERAMIC LAMPHOLDER AND THE LAMP WILL WORK WITHOUT BALLASTS OR IGNITORS.THE LAMPS WILL GIVE HIGH POWER METAL HALIDE LIGHTING WITHOUT THE NEED FOR EXPENSIVE CONTROL GEAR.DUE TO THE HIGH OUTPUT OF THE LAMPS THEY GENERATE HEAT AND WILL REQUIRE A WELL VENTILATED FITTING WITH GOOD AIRFLOW TO PREVENT THE EARLY FAILURE OF THE LAMP. WE HAVE BEEN INFORMED BY NUMEROUS CUSTOMERS THAT THESE LAMPS ALSO WORK VERY WELL AS GROW LAMPS, DUE TO THE LAMP BEING BALLASTED USING AN INTERNAL LINEAR HALOGEN TUBE. THE HALOGEN TUBE ILLUMINATES ALONGSIDE THE METAL HALIDE VESSEL THUS GENERATING A GREATER LIGHT SPECTRUM (YELLOW FROM HALOGEN & DAYLIGHT FROM METAL HALIDE) WHICH IS IDEAL FOR DIFFERENT GROWTH STAGES OF A PLANT.