Rainbow Water Prism - Cubie Rainbow Maker - Six Sided Crystal Glass Suncatcher Handcrafted from 6 facets of crystal clear glass. Measures approximately 3 inches long by 3 inches wide. Fill prism with distilled water through opening on top. Prism fills room with rainbows when hung in sunny window! When the direct sunlight moves away, you still have a pretty sculpture hanging in your window.