After each cleaning, it empties itself into a Dirt Disposal bag that takes up to 60 days to fill, so that you can forget about vacuuming for months. Using the iRobot Home App or just your voice with Google Assistant or Alexa, you control when your robot cleans. With the i4+, you can check vacuuming off your to-do list.iRobot Roomba i4+ Robot Vacuum Self Emptying Smart Navigation Powerful Pick Up 20% larger battery for extended runtime compared to Roomba i3/i3+ Robot Vacuum Cleans up after you with the Clean Base Automatic Dirt Disposal allowing the i4+ to empty itself for up to 60 days Powerful performance with a Premium 3-Stage Cleaning System and 10X the Power-Lifting Suction Control how you clean with the iRobot HOME app or your voice assistant Smart navigation maps your home using advanced floor tracking sensors for effective cleaning on hardwood and carpet