VIVOSUN 4FT 54W 6500K T5 HO Fluorescent Tubes Cool White Grow Light Bulbs Pack of 5 COOL, BALANCED LIGHT: Premium VIVOSUN T5 lamps emit a balanced blue and violet spectrum at 6500K to promote vibrant vegetation and prevent stretching LONG LASTING: The average recommended usage life is well over 20,000 hours, exceeding the lifespan of almost any HID lamp GENTLE ON SEEDLINGS: 54 Watt bulbs put out 5000 Lumens, nurturing seedlings and tender foliage safely even at close range and in cramped spaces Package Includes: 5 bulbs) ECONOMICAL: VIVOSUN T5 lamps are cost effective an efficient. Also, very low heat emissions reduce or eliminate the need for expensive ventilation and air conditioning HIGH QUALITY UNITS, GREAT CUSTOMER SERVICE: VIVOSUN produces premium lamps backed by friendly and professional 24/7 after-sales support Length: 48&#039;&#039; (4ft) Power: 54W CCT: 6500K Luminous Flux: 5000 lm Color Rendering Index(CRI): 82 Lifespan: 20,000 hours VIVOSUN T5 grow light bulbs give vegging plants the light they need to grow strong and flowering plants the spectrum they need to make flowers bloom and buds blossom ; -COOL WHITE 6500K for veg ; -WARM WHITE 3000K for flower ; The florescent tubes are wrapped in bubble wrap and secured inside a thick, extra-fortified cardboard tube. Shine 5000 Lumens down onto your plants per tube- brighter than other name-brand lamps ; All VIVOSUN T5 florescent tubes are HO (High-Output) tubes, which produce far more lumens than standard or HE tubes ; Constant brightness that doesn&#039;t flicker on and off ; With low heat emission and energy-efficient, your plants will love them ; It is perfect for commercial and industrial applications also :  Aquariums, greenhouses, propagation, germination, general office  lighting.