We got the size large and it's perfect for our Border Collie. The pad on the bottom is thick and the sides are sturdy. In the winter when he's cold or tired, he likes to curl up and snuggle in the bed. We use this bed mostly in our house. When we go on longer winter trips in the car or will be inside for a while, we take this dog bed along for the ride. We return to the car and he's curled up inside.
The size large is perfect for our Border Collie. If you have a larger dog, you may want to choose a different product because this is as big as they sell this brand.
Overall our dog is very happy with his new bed, inside our home, or in the car.