A thing that comes in very helpful. Both the power cord and the safety cable that come with the package are reasonably long. Important: the device will not function unless it is connected to a power outlet and has a power cord plugged into it. There is sufficient fluid in the built-in reservoir for approximately ten standard surfaces. If you only wash your car once a year, you will need to perform two or perhaps three separate runs, each time spraying the cleaning solution in the direction that the robot will travel. It was necessary to replace the rag-slippers every three to four windows; however, this was due to the fact that the windows had not been cleaned in a very long time. In general, even very dirty ones leave strong stains. Even after being washed in a typewriter, the filth that was on the clothes will not be totally removed even though the clothes will dry very quickly. During the entirety of the work, which included approximately 30 surfaces and four walls in the bathroom, the robot did not fall off of any of them. On occasion, it became entangled on the window elastic and started to squeak invitingly; however, it must have sensed that it was beginning to peel off because it halted its forward movement. In any event, I cannot speak highly enough of this robot given how well it performs its duties.