This is a very nice sized pet pen.  We use it for our two kittens.  It's large enough to hold a litter box and gives them plenty of room.  We still put them in it at four months old and they have no problem staying in there for awhile.  Great if you're traveling.  At home we'll keep it set up and leave the door open and they'll often times go in there and go to sleep in their bed we keep in there!