Soft sided crates
I love using soft-sided crates when I need something light and quick to assemble, for example when I take puppies to vet appointments and I dont want them to have contact with the environment.
They are lightweight, fold down, and easy to carry. They are awesome when a group training class requires a crate. The crate provides a clean and cozy space for the dog to hang out during the "lecture," waiting for our turn to practice.
However, the dogs should not be left unattended in these crates until they are completely crate-trained and you are confident about the dog's behavior in your absence.
These crates unzip, get flipped over, and the mesh rips very quickly with the pawing and chewing of a lonely dog. These are very hard to clean out in case of accidents!