SiliconeZone Shell Tray Butter Mold, Bright Blue Made of Soft, flexible Silicone; They are great for Ice Cubes, Chocolates, Jell-O and Butter. Made with FDA approved pure food grade silicone, it has no bulk fillers; Oven, microwave, freezer and dishwasher safe Even heat distribution; Quick and even cooling: Can go from -58 degrees F to 572 degrees F Non-stick finish will not retain odors or flavors; Rinses and wipes clean easily Flexible for easy removal; Can be folded for easy storage