I cannot tell you enough... THIS.THING.IS.AMAZING!!! My 6 year old pitbull (about 50 lbs) LOVES getting under the covers, esp at night, and I wake up so hot. He now sleeps inside of this bed ALL Night!! woo hoo! I bought the Large size in the tan color. The opening is a little tight so sometimes I have to open it for him. Even for the times he cant figure out how to crawl in it, he sleeps on top of it! Just great!