The Simply Clean Litter Box System has no visibly exposed moving parts. The litter bowl rotates slowly at a rate of one rotation per hour. So, the system is quiet, safe and convenient for you, your family and your pet. The Simply Clean Litter Box System reduces odor-causing bacteria by continuously removing waste from the litter bowl and moves it up the conveyor system. The waste is then discarded into a built-in receptacle automatically, 24 hours a day. So, your cat's litter box is always fresh and ready for use.