6 Pack Silicone Spill Proof Stopper, Compatible with Stanley Cup 2.0 40oz/ 30oz, Tumbler Accessories, Including 2 Straw Cover Cap, 2 Square Spill Stopper and 2 Round Leak Stopper

My daughter was gifted a Stanley for Christmas. She brought it on a road trip with us and the amount of times it would get knocked over in the car and leak water was infuriating. For such an expensive cup you would think they wouldn't leak. I heard about plugs you could get and ordered these. Zero leak what so ever now. Definitely recommend if you have a ridiculously Obey priced, leaky Stanley.

This works great! I didn't know that I was not going to have an issue of the Stanley being too leak-proof! This product works so well, that I have to try harder to get liquid through the straw because there is no negative pressure in the cup. If anyone else ends up having this issue, just blow bubbles through your straw into the liquid to increase the pressure and you will have no problems drinking! I am very impressed with how leak proof this is!

I ordered this for my 40 oz travel mug to see if it would fit and keep it spill proof. Well, I can tell you it fits perfectly. I looked at the hole cover and the hole and thought, there's no way on God's green earth this is going to fit and if it does it's not going to go on easily, but it does and it did!Lol, I'm not sure I want to find out how well it stops leaks by creating a leak but I will.Ok, so I just tipped it over on it's side and while it didn't completely stop my cup from leaking it significantly stopped it enough to give me time to grab it up and keep it from making a mess!That's great in my book! Plus, I like the straw cover so that I can keep flies and other insects out of my drinks.All in all this is a great set to have!

hi! i love them ofc but there's one teeny tiny thing you need to know, 1. so when i got them they were dirty but i washed them and the dirt went away! 2. thankfully it works!! 3. when all of them are on it makes a suction sound and it's hard to suck out of thestraw, so i had to keep one of them out ( the cylinder one on the bottom of the lid) and so it stopped suctioning but.....it still leaks!!! but i do think it is my fault that it still leaks but this is just a little warning so your lips aren't hurting after a while of you drinking lol well bye bye!!Edit. Also u you ou can get a sharp jawline if you use them all. Jk jk lol

helps with spilling soooooo much but some of the pieces are thick and u can tell a little that u have it on ur stanley.

I put these on my Stanley dupe and they work perfectly

Definitely prevents spills and even air from coming in. Each time I sip, it creates a vacuum inside the cup and when I stop, a large bubble of air forms. Basically can only use the straw part, which is ok since most of my leaks are from tilting on that side. If anyone has ideas on how to vent the inside so I can use the other part, please share.

The media could not be loaded.  I’m a bit disappointed but should’ve known for a cheap item. The silicone that’s supposed to prevent it from spilling has a little slit in it.