I have ordered the Kärcher with skepticism, since I had just about all conventional methods and also a window robot to clean my being too many windows in the house, tried. So unpacked, loaded up battery fully prepared concentrate and to work! I must say I'm thrilled! It's very light and streak-free, only the frame and if you do not clean the device performs one must wipe briefly with a Kleenex, which goes very fix without leaving streaks. In my 'Test' then I have a partial success six terrace windows and five large windows, the sides of the front door and the mirror; cleaned) in half an hour. When I think that the last window cleaner has cost me 110, I must say that it was a very profitable for me acquisition. The unit is very well made, it is a short and a long suction lip here, and the Einsprüher. It is only 20 ml concentrate here which is not really enough for a long time, so I recommend the appointment of the concentrate offered here too by Kärcher. As an additive should be noted that the window sucker is also great for tiles or stone kitchen plates, I had the kitchen plate ratzfatz schlierenfrai clean.