The Marineland Half Moon Glass Aquarium's unique shape and LED lighting make a stunning combination. The LED light provides a shimmering effect in the water that mimics the natural underwater effect of sunlight. It is energy efficient and powered by a low voltage adapter. Each aquarium has a black plastic framed bottom and a clear plastic canopy with a feeding hole, and cut outs for the filter. The canopies also help to reduce water evaporation and keep fish inside the aquarium. The Half Moon design offers a 180 degree seamless view of the 20 gallon aquarium.