Absolutely the best dog bed that I have ever purchased! This bed is made of a nice thick material that you can zip off to wash. The the interior is sewed together and stays in place with outer cover is removed. The shape stays in place when your dog lays on it. My dog is over 8 years old, a Border Collie, and I ordered the largest size. She likes to stretch out to sleep and the bed is a perfect size. My dog loves her new bed!!!