Plexiglass acrylic globe is clearer and 10 times stronger than glass. Generously sized orbs provide a great environment for fish with more swimming space than a traditional fish bowl. A combination of 5 biological, mechanical, and chemical filtration stages keep water crystal clear and free of pollutants. Can go several months between filter changes. Filtration system and air pump are almost completely concealed in the bottom of the orb. A beautiful example of living art, the BiOrb Aquariums combine the clean, modern look of a traditional fish bowl with the performance of a high-tech aquarium. The unique shape of the BiOrb gives you an unobstructed 360° view of your fish in an environment that's free of wires, tubes, and other distractions. . . . . . Low voltage 10-watt halogen bulb is hidden inside the lid and provides beautiful illumination for the entire tank. A single transformer simplifies the set-up by providing 12 volts of power to both the air pump and light. Suitable for both tropical or cold water fish. "Swap Tops" let you change the look of your BiOrb to match its surroundings.