This scoop free litter box is great! After the box senses a cat, about 20 minutes go by and the automatic rake starts moving the solids into a trap door. It’s very quiet, you honestly don’t hear the rake moving. For one cat it lasts 30 days. It doesn’t completely eliminate odor since the solid waste is tucked under the door of the box and it’s slightly exposed. I just end up cleaning out the solid waste once a week and it eliminates that issue.