Hoover UH60010 Self Propelled Bagless Upright Vacuum Equipped with Hoovers patented WindTunnel Technology, this bagless upright vacuum cleaner effectively lifts and traps dirt and debris, so it ends up in the cleaner not scattered back out onto the floor. With red and green lights, its embedded DirtFinder system indicates areas that need more cleaning attention. The green clean light remains on while vacuuming except when the detector senses a larger amount of dirt then the red dirty light will illuminate to suggest additional vacuuming in the area until the light changes back to green.