Perfectly compatibleThe straw covers are compatible with Stanley 40 OZ tumbler straw and most straws in diameter 0.4 inch(10mm).This will be a very practical and durable gift for your friends or families.Food Grade MaterialThese straw covers cap are made of food-grade silicone without BPA,reusable, elastic, odorless, hand washable and dishwasher safe. Not only can it be decorated but also can increase children's habit of drinking more water.All-round Spill ProofThe straw protectors helps prevent from dust and beverage spills ensuring the straw clean.and also prevents mosquitoes from entering the water cup, keeps the straw and cup hygienic. Especially suitable for outdoor activities.Stylish & PortableOur straw covers tips lids is small,you can carry and use it anywhere, suitable for various outdoor activities,such as walking in the street, camping, hiking or other activities.Straw Lid Kit 4 different flowers may attract a lot of people's attention in shape, and when you use it, it will make you feel good and can remind you to drink water.A variety of cute patterns also helped to distinguish the crowd to avoid the embarrassment of holding the wrong cup.