The material is food-grade silicone, non-toxic and tasteless, safe and environmentally friendly, in line with the German and the United States food contact with the commodity standards (LFGB and FDA). High and low temperature, the use of temperature range -40 Celsius ~ +240 Celsius, can be used in refrigerators, microwave ovens, toasters. Due to the excellent elasticity of silicone, it naturally forms the internal negative pressure state when covering the container, completely isolating the flow of gas inside and outside, and the sealing performance is unparalleled. Used in the refrigerator to cover the bowl, pots, pots, etc., will not string flavor, due to completely cut off the air into, can achieve the best preservation effect. Small thermal conductivity of only 0.27, is about 1/1000 of the metal used to cover the bowl, pots, basins and other insulation effect is excellent. Silicone rubber composed of silicon anti-aging, under normal circumstances, the service life of up to 30 years. According to the size of the current household commonly used containers, offers a variety of size cover to choose from. Specific six dimensions are: Diameter 6.5CM 9.5CM 11.5CM 14.5CM 16.5CM 21CM, Type: Bakeware Material: Silicone Package weight: 0.266 kg Package size (L x W x H): 23.00 x 23.00 x 1.00 cm / 9.06 x 9.06 x 0.39 inches Package Contents: 6 x Silicone Fresh Cover