Directions to put together were simple but execution was not so easy.  The side bars tended to twist and I finally had to put it upside down flat on the floor to pull the Velcro flap closed.  The Velcro just barely stretched enough to catch the other strip.  I placed a pillow and my dog's blanket over it.  My dog then jumped in the middle and lay down.  The medium bed enables my 12 lb. dog to stretch completely out on his side if he chooses.