KINGSO Cute Anti-dust Cartoon Silicone Glass Cup Cover Coffee Mug Suction Seal Lid Cap Blue Butterfly Material:food-grade silicone, safe and non-toxic Size: 10.5cm/4.13"(diameter of cup cover) Package included: 1pcs cup cover Notice: becaues the pattern of cup cover are not same, size are different How to use: To enable airtight sealing, press the cup cover slightly till it is sucked.