Future Harvest Development 900234 Sun Blaster 10000K T5HO Replacement Bulb, 4-Feet Sun blaster 6400K T5HO lamps simulate natural sunlight and are ideal for cuttings and vegetative growth For maximum output and efficiency use with Sun Blaster T5HO lighting fixtures Specialty lamps are available in red, green and blue for those that wish to create interesting visual effects for home, office or store front