3 Removable Covers: Use the covers to stack the ice cube trays to keep the ice cubes clean and protect them from odors collected from the freezer. Seal the lid to prevent leakage (Note: The lid cannot be placed in the dishwasher or oven). Silicone Material (Food Grade): Ice cube trays are made of silicone and PP and are BPA-free and LFGB certified. It has no peculiar smell and is more suitable for making pure ice cubes. Easy Release with Silicone Base: The unique design of the silicone base makes it easy to remove ice cubes. Rinse the bottom with water. Press the bottom and the ice cube comes out quickly. Mini ice cube tray: Each tray contains a total of 6 large cubes (3 x 3 x 3 cm) out of 18. Easy to clean and reusable: Withstands temperatures from -20 to 100C and is safe for use in the refrigerator and microwave. Perfect for the freezer and for storing baby food.