Roomba's Keep-Out Zone Sensor. Set of 2. I'm selling these because I no longer need them after buying a new vacuum cleaner. There are some minor scratches, but they are still usable. Please check the photos for the condition. Operation has been confirmed. The batteries are the ones that were in use, but I don't know how much charge is left. Please understand the above before purchasing. ・Power source: 2 x AA batteries Shipping via Takkyubin Compact.