Helios Metal Halide HQI Light Bulbs use state of the art technology and innovation built into every HQI bulb. Combining our inherit knowledge of the hobby and our expertise in lamp engineering, Helios Metal Halides define performance and delivers the assurance of quality. An infrared light is incorporated in every bulb manufactured, a unique feature our engineers have made possible. Infrared light is used to aid in the photosynthetic process and is an important variable for both photosynthetic algae and bacteria to thrive. Available in either E39 mogul sockets or DE double end HQI and in 12,500K and 20,000K color temperatures.