Silicone Spill Proof Stopper for Stanley Cup 2.0 40oz/30oz Tumbler Leakproof Spill Stopper Set - 4 Straw Cover Sets, 4 Square Spill Stoppers,4 Round Leak Stoppers (12 PCS transparent)

I have been a long time user of the ‘flask’ brand of cups and bottles, which are all spill resistant. You can imagine my surprise when my daughter received a Stanley cup as a gift and repeatedly spilled water all over me, the kitchen, our car, her room, etc. At first I thought it was the lid - replaced the lid, NOPE. Still leaked. Searched Amazon for Stanley leak stop and came across this set. I ordered the plugs, cap and straw topper and they arrived quickly.I tore open the bag of magic when the Amazon man rang and a literal genie appeared and handed me the Stanley straw and lid plugs. I immediately placed the plug in the straw hole, opened the lid to place the round cap (it goes inside on the spinny thing on the lid - I believe that’s the technical term), then placed the straw plug on the straw and VOILA! You can literally turn your cup upside down, even do a little dancey dance, and as long as you are using a standard size Stanley straw (or equivalent), your precious beverage will not spilly spill.An important thing to note: You must keep the lid ‘spinny top’ (sorry to get so technical) OPEN in order for the plug to function properly. The plug will not work if you try to place the straw hole in the spinny lid over the plug. It’s fine. Everything will be fine. Keep the spinny top open to the side and enjoy your spill-free Stanley sips.Also of note, we kept extra so that when messy kid’s messy friends bring their spilly cups over, we put the plugs and caps on to avoid more mess.These are a GREAT value for the price. They are easy to clean and have maintained their color. They are thick silicone and good quality. I wish I would have ordered the larger pack, but we will definitely order more.Oh! Even if you have some cute straw topper, these come with a straw plug which both protects the straw AND keeps your drinky drink from spillong out.Overall, worth their weight in gold.

I love the way they work, no leaking. I'm going to order some more.

The media could not be loaded. It works really well much better than another one that I got those from a different brand, but it is kind of difficult to get the topper on because the hole is much more smaller than the actual straw is you just have to stretch it out a lot but I’m not gonna use the topper. I’m just letting people know who want to use the topper. Beware I wouldn’t say it’s just difficult, you have to put strength into it

Works like how it’s supposed to, but does make drinking a little difficult/ weird

I was a little skeptical about ordering these stoppers, but they actually work! They are amazing! These little rubber stoppers really do make your Stanley cup spill proof. The price is great and you get 2 sets in your order!! Will definitely buy again. Absolutely recommend these for your Stanley Quencher H2.O Flow State 40 oz, perfect fit!

I was so sick of my daughter’s Stanley’s leaking. These work great on the 30 oz handle ones. Zero complaints or leaks, even tipped upside down!!

Really works!!! I was amazed. You may get a little drop if it’s knocked over really hard but 99.5% of the time there are zero spills. It’s a game changer!! Our volleyball association actually put out a memo that “popular brand cups” were not allowed in the gyms ever without this three part system. Yes cap is a little tight but once you donut a few times you learn how to do it quickly. Like someone said if you don’t like the topper just use another but can’t guarantee that won’t spill. Make sure to clean every piece often. Mold will grow in between the silicone and the cup or mouthpiece.

Works perfect