SunBlaster 48" (4 ft or 122cm) T5 HO Fluorescent Grow light Ballast with Full spectrum 6400K, High Output, 54 watt SunBlaster grow light bulb. Sun Blaster T5HO (High Output) Fluorescent Grow Lighting Kits provide everything you need to get up and growing fast! Each Sun Blaster T5 HO Grow Light kit includes the latest, most efficient electronic ballast, a 6400K Full spectrum grow light bulb, a power cord with roller switch, a jumper plug and both hanging and flat surface easy mounting clips. All SunBlaster T5HO fixtures link together easily, regardless of length, to a maximum of 8 per single power cord so it doesn't get easier or better than that, you can expand or decrease your grow area any time. Use SunBlaster T5HO lighting to provide supplemental overhead and side lighting, as well as additional light for tall plants when hung vertically. The slim design of Sunblaster's new T5HO's allows them to fit virtually anywhere you need additional light for growth. With Sun Blaster's T5HO Grow Light Ballast, each New Edition T5HO has been re-engineered incorporating the most advanced on board electronics in the industry. All SunBlaster T5HO grow lights are driven at the optimum temperature, lowering heat production and extending lamp life. Included in the fluorescent grow light kit is SunBlaster's new T5HO grow bulb, the New Edition T5 HO fluorescent grow light bulbs have also been re-engineered incorporating a "Cold Chamber" ensuring that the small amount of mercury gas is kept at the most efficient operating temperature to produce maximum light output. SunBlaster T5HO grow light kits are available in 2' ft (61cm) 24 watt 6400K, 3' ft (91cm) 39 watt 6400K and 4' ft (122cm) 54 watt, 6400K full color spectrum for vegetative growth. Be sure to use SunBlaster's new Nanotech reflectors with these or purchase the combo kit instead to generate up to 300% more light on plants.