I like this one, but I am afraid to spend $50 on it, they have to walk up a ramp and into the box inside the dome. A couple of mine are skittish and I am thinking they might find being that closed in stressfull.

http://www.pet-dog-cat-supply-store....booda-dome.php



btw I use the white litter crystals, I think that's why I can get away with two for four.....just.