Born for Stanley/Yeti Tumblers Unlike the common multi-piece cylindrical ice molds, this ice cube tray features a hollow cylindrical ice cube in one piece. The ice cube size perfectly fits the cup body, making it very compatible with Stanley and Yeti 30-40Oz Tumblers. It is easy and convenient to use, requiring no repeated extraction and stacking of cubes just place it directly into the cup to enjoy your cold beverage.