Sorry it took me so long to reply and now it's too late to go back. I bought my sister a robot vacuum cleaner and when I brought it to Massachusetts we were very disappointed that the machine didn't work. I got him checked out by a techie and he was dead on arrival. She doesn't want me to replace her and so it goes. Be careful when you buy this machine. Make sure to return it immediately if you encounter any problems so you don't lose around $100.