I bought this robot vacuum cleaner for two reasons. one). It got good reviews and 2) because it has a long lifespan and I have a big house. Runs like crazy! The only problem I have is that I have a lot of dark colored carpets on my tile floors. Doesn't work on dark carpet. With the help of Revain and YouTube I found that you can take plain white paper and put packing tape on it to make it shiny and reflective. Cut out three rectangles to cover the three sensors on the bottom of the Hikins Robot Vacuum. They are located next to two large wheels and a small middle front wheel. Seal each of the sensors with tape. Now my vacuum cleaner cleans all my dark carpets with no problem. I am so happy with my purchase now!