LUOLAO Silicone Spill Stopper Compatible with YETI Straw Cup, Mug Tumbler Accessories Including 2 Straw Cover Topper Cap, 2 Leak Proof Stopper

These work perfectly for my yeti cup! No leaks at all!!

Fits my yeti straw perfectly

Works great on sealing out dust and dirt, or any leaks if spilled over. The seal is so airtight that I have to pull the straw the whole way to the stopper, otherwise my water will shoot out of the straw. Afterwards, slowly push your straw to the bottom of your cup, and cap.

These items work very well, up to a point. It really depends on what you’re drinking. I have found that they are indeed very airtight, and do prevent leaks. However, they are so airtight that when you close the lid the liquid just shoots up the straw. You have to be very careful when putting the lid on and very slowly push the straw down. The first time I used this, it was with sparkling water. I cannot believe the mess it made when I pushed the straw in, so I have learned to do just what I advised above. Other than that, these work pretty good.

Those are su practical and perfect to my Yeti