scoop free auto litter box
this thing does not work for 30 days, not even for 20.it works for about a week, 10 days at most, and after that it starts to smell progressively and becomes unbearable pretty soon. i think it is too expensive to change the carteiges so often. if i new it is going to be like that at the time of purchasing, i would never buy this product. i even tried electric air cleaning systems with it; does not work. with air fresheners it becomes even worse. I would not recommend this product.