10mm Straw Cover: This straw cover is specifically designed for stanley cup straw. perfectly compatible with stanley 30&40 oz tumbler with handle straws, And our straw caps are also suitable for all types of straws with an outer diameter of 10mm. Please confirm the size of your straw before purchase!High Quality Material: Made of food grade silicone, these straw lid are durable, safe and non-toxic, reusable, hand washable and dishwasher safe. Dustproof and splashproof, especially suitable for outdoor activities.Leak-proof: prevents the straw from being contaminated by dust and spittle in the air, and also prevents mosquitoes from entering the water cup, keeps the straw and cup hygienic.Easy to Use: The soft 10mm straw cover is easy to put on and take off, it attaches to the straw and when you open the straw cap to drink, they hang on the side of the straw so you don't get lost.Perfect Gift: Straw covers make great gifts for friends and family, the cute shape will be loved by your family and friends. The straw cap are perfect for decorating your stanley cup. Adding silicone straw plug to the straw can add a lot of party fun,kids and adults will love them.