We got three of the XXL to attach together. I couldn’t be happier! They attach nicely, which is a feature I couldn’t find in most other crates. Building them was pretty easy. The hardest part was making sure the top metal pieces worked from crate to crate to attach them correctly. I had to redo one of them because I had the pieces mixed up and the instructions didn’t state that that would be an issue. Overall, I love these!!