24 Pcs Reusable Ice Cubes, Colorful Plastic Ice Cubes, Refreezable Ice Cubes, Non-Diluting Square Cubes, Washable Quick Frozen Ice Cubes for Drinks Cocktail Whiskey Coffee, BPA Free

As opposed to plastic ones I suppose. https://www.walmart.com/ip/24-Pcs-Reusable-Ice-Cubes-Colorful-Plastic-Refreezable-Non-Diluting-Square-Washable-Quick-Frozen-Cubes-Drinks-Cocktail-Whiskey-Coffee-BPA-Free/20135423705