Key Features Pack of 3 Sea Urchins Natural colour effect For use in all BiOrbs and other aquariums Adds interest to any display Genuine BiOrb New to the Oase BiOrb range are the realistic and fun looking Sea Urchins. Available in a Natural effect, this pack of 3 small ornaments can be added to any Biorb or fish tank display to add interest and a decorative look. The ornaments can be placed around the base of the display to blend in with any pebbles or ornaments. All decorations should be rinsed prior to placing in a tank.