This is a wonderful dog bed as both of my pups will attest.  I already had a dog bed for our 20 lb. resident dog but when we decided to foster a cute little terrier mix we decide to order another bed.  We love the removable fleece liner and it is soooo soft and fluffy.  This was also a great value compared to our local retail pet store.  The medium size is a perfect size for the 20 pounder.  The little foster pup is under 10 lbs. and could easily use the small.