I bought the straws to use with my Stanley cups, and they fit just fine. I really like the neutral colors, but I didn't realize how soft they were going to be? Now I realize it says silicone in the description, but I've purchased other silicone straws before, so I was not expecting them to be that soft… that is why I gave it only four stars instead of five, because I don't like the texture, or the way they felt when I took my first sip, it definitely felt strange at first, because you're drinking out of a rubber hose basically, and I thought they were going to be a harder plastic material, like the clear plastic straws that come with the Stanley cup, but they are very different.
They are also too long to use with my other Dunkin'' Donuts and Starbucks cups, unless I trim them to fit, which is probably what I'm going to do, but the cup holes might not be big enough to fit these straws because they're a thick rubber material. I guess I'll find out when I try it.
Overall, I'm happy with them-they do what they're supposed to do.
Note: I have used a few of them already, so not all of them are shown in my review photos, but this set came with a few tan, beige and cream colors not shown.