It is a whelping box... It has an extra pen area that has puppy pads in it that they can go on. I made the sides taller so that my cocker can use the same box for whelping her pups in. I personally think my yorkie was ticked off because I took the maltese with me instead of her. That is the only reason that I can think of for her not to use the potty pads. I have always kept the pads in the same place in different spots of the house but she didn't use them yesterday. I had an x-pen but it was in my van when I had a wreck and it burnt up. I don't have the extra money right now to buy another one. My yorkie had a c-section and then developed mastitis. I have spent alot of money on this litter and the care of the mom so I don't have any extra money right now. As soon as I do I am planning on replacing my x-pen. I also lost my income when I had my wreck because I groom dogs and all of my equipment was in my van when it burned up.