Prevent spatters in the microwave or on the hob, or use to help retain moisture in dishes as they bake in the oven.The pure silicone construction of the lids is heatproof to 220C and can withstand freezing to -40C. They are particularly good for use in the microwave on the hob, as the flexible nature of the material will allow any build up of steam to be released automatically and harmlessly, while preventing any of the food from escaping.