Food grade high quality silica gel material, safety guard, convenient and durable, easy to deice.Can withstand high and low temperatures, -40 to 220 degrees Celsius. Used for refrigerating/microwaving/cooking ice cubes, jellies, puddings, chocolates, candies, etc.The inner wall is smooth, the bottom is smooth and easy to demoulding. 4 3/4" L x 9 7/16" W