3 Pcs Silicone Spill Proof Stopper, Compatible With Stanley Quencher H2.0 Tumbler 40/30/20 oz, Leakproof Silicone Seal Kit, Including 1*Straw Cover, 1*Straw Hole Seal, 1*Center Shaft Seal (H2.0)

I purchased this item because I am constantly tipping over my Stanley and after a week of using it I can say it has worked just how I intended it too. When purchasing it's important to look into which Stanley you have because they offer multiple versions for different Stanley's. The one I bought fits my Stanley H2.0 perfectly. I have knocked it over several times and I have not noticed any leakage. The only problem I ran into was having to look at the center shaft cap because I wasn't getting any oxygen into my Stanley when I drank causing the pressure to build up and not getting as much water. After looking at it closer I found the cap had a little latch on the bottom that I opened and I haven't had any problems since.

Bought one of these cuos for my 9yo daughter cause it's the cool thing the kids want. It's not practical though because in it's standard configuration, it leaks if not standing up straight, or more likely gets jostled around or knocked over in her back pack as again, she is 9. I was skeptical, but figured for the price give it a shot. Well, it works exactly as advertised. Color me surprised. Now my daughter can be one of the cool kids, Yay!!

The title is a little deceiving I thought I was getting a three pack of each item not just one of each. The straw hole cover is a bit of a pain to put on but it works when you use all three there are no leaks

Definitely works well to prevent leaks and spills - even without the straw cover on, it helps to prevent spills when carrying the cup at an angle (which happens when I’m carrying multiple things at once). A little tricky to get the silicone mouth piece part on the first time, but after some trial and error, it’s easy. Super important to take the pieces off and clean them properly, I could see where it would get funky if you forgot to disassemble it when washing. Still 5 stars though, because it works!!!

I used this on my 30 oz Stanley and it works great! Completely spill proof. At first, I was a little confused about how to put on the piece that the straw goes through but I figured it out and it is very good now.

The product is a silicone cap for the straw, a silicone seal for the straw opening and a cap for the center piece under the Stanley lid. I tested the Stanley by tipping it on it's side before applying. The cup dribbled a lot. I then added the caps and seals and tried again. The dribble was slowed down, but the products didn't stop the leak. Therefore, I will give three stars for helping prevent a big spill, but it's not close to leak proof. You could definitely NOT put this in a bag or even leave it tipped over for long. However, it WILL help prevent catastrophic spills and give you time to right the cup before much liquid spills out.

I love my Stanley, but with the original lid it would spill all over the place if it got knocked down. I decided to give this a shot and I was pretty surprised to see it actually worked. So far it has been pretty durable, the color is like a slate gray, the size is barely noticeable, you can’t taste plastic while drinking from it like a normal cup which is also nice, overall it’s fairly versatile.

I really didn’t want to buy another water bottle but needed my Stanley to not drip when I threw it in my teacher bag. These little plastic attachments work great!

I have a 30oz this does not fit it ordered on 12th January waste of time and money.