14,000K 400 watt double ended HQI metal halide lamp. A bright mix of blue and white light producing a crisp ice blue color. This bulb is brighter than a 400 watt 20K double ended bulb and is a great choice for reef tanks. This bulb will bring out fluorescence in corals & fish well. Must be used with a 400W HQI ballast or 400W electronic ballast.