Product Features: WILL NOT fall down stairs. Sensors prevent KOOLVAC from going over an edge. Koolvac Robotic Vacuum Cleaner is Easy to use; simply program the room size and let it run. It will automatically shut down when it's finished. Koolvac Cleans thoroughly with its combination of vacuums and brushes. Compact design lets it get to those hard to reach spaces. Koolvac Robotic Vacuum Cleaner has internal sensors to detect obstacles like walls and stairs. Cleans any type of surface. This Robotic Vacuum Cleaner is Lighteight and automatically shuts off when picked up. Battery lasts up to 90 minutes.