For more info on the SmartSift: http://www.bigappleherp.com/Hagen-Catit-Design-SmartSift-Automatic-Sifting-Cat-Litter-Box The Hagen Catit SmartSift Cat Litter Box automatically sifts through a simple and innovative lever system. Simply pull the lever once a day and waste will be separated from usable litter and moved into a separate waste bin. At the end of the week, simply pull out the waste bin and easily pull out the bag. Litter clean up has never been so easy and sanitary.