Fashionable Design.. Wide Compatibility..for 30 and 40 oz Stanley cups.. Simple Modern,Yeti, Owala, Hydro Flask, Maars, Meoky, MaxBase, Beast, Hydrapeak, and more. It comes in a pack of 4 colors cowboy hat straw caps: white, pink, black, brown. They slide on your straw easily and stay on securely.and comes with a case to car them in.. Protect Your Drinks: Our silicone straw covers not only prevent dust and spittle from contaminating your straw and cup, but they also keep mosquitoes out of your water. This dustproof and splashproof design makes it ideal for outdoor activities. Enjoy a hygienic drinking experience wherever you go…brand new in packaging..