The easiest way to make four large crystal-clear slow-melting ice spheres (2.36" diameter) or cubes (sold separately at Wintersmiths.com) for cocktails in your home freezer with tap water. Perfect for whiskey, scotch, rum, tequila, mixed and non-alcoholic drinks. The patent-pending design employs directional-freezing to remove and isolate air bubbles and impurities allowing you to extract four clear ice balls or cubes for your drink. Made out of durable BPA-free plastic, FDA approved food-grade silicone, and EPE foam.