Straw toppers for stanley cup are made of high quality food grade silicone material, BPA free, safe and healthy, reusable, environmentally friendly, durable, hand washable and dishwasher. This size is suitable for stanley 10mm straws,easy to put it on and take it off quickly. This model Silicone Straw Covers Cap is perfectly compatible with Stanley 40oz 30oz tumbler straw and compatible with Simple Modern 40oz Straw in diameter 0.4 inch. The straw cover can seal your straw, so that it can prevent dust when not drinking, or prevent drinks from spilling during moving, a good helper for outdoor activities. The reusable straw cover are are made of food grade silicone, durable, reusable and BPA-free material. It's safe and reliable to use. Polar Bear Straw Cover Cap,Good choice for a gift,this Love heart stanley cup straw cover,It looks very cute, easy to put on and take off when using, the main thing is reliable quality. It is the best gift for Lover Couple. 1