LED light fixtures are available in 20", 24", 30", 36", 48" and are designed for full-coverage lighting on standard sized aquariums. Included with each fixture is one Day White LED lamp! Two expansion slots are available for additional Day White LED lamps or Colormax LED lamps. Energy-saving LED lamps use up to 70% less energy than comparable T8 fluorescent lamps and do not contain mercury, which is harmful to the environment. Mounting legs are pre-installed and easily adjust to fit your aquarium. The three-position power switch includes Moon Glow accents. The LED lamp connections are moisture-resistant and connect effortlessly into place!