Solve the problem of unsuitability: When purchasing a straw cover, are you concerned about the size not being suitable for multiple different brands of straws or cups. The adjustable straw cap can help you solve it. This is a great innovation. Fit All Brand of Straw: design with adjustable internal diameter (6mm-10mm). Suitable for all brand of for Stanley, for Simple Modern, for Yeti, for Owala, for Hydro Flask, for Reduce, for Maars, for Meoky, for MaxBase, for Beast, for Hydrapeak and so on. NO brand limitid. Food Grade Material: Made of the same food grade silicone material. durable, safe and non-toxic, reusable. Dustproof and splashproof, especially suitable for outdoor activities. Hand washable and dishwasher safe. Leak-proof & Dust: 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. Colour:translucent Material:Silica gel Package Contents: 4 x Suction straw dust plug Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.