Rainbow Water Prism - Large Diamond Rainbow Maker - Glass Crystal Suncatcher Handcrafted from 6 facets of crystal clear glass. Measures approximately 9.5 inches long by 2.25 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.