This window sucker is very helpful. If one makes the guide sequence and previously prepurified heavily soiled windows are no stripes, and I believe it also extends the life of this equipment. Assist is important in any case. Especially the windows exposed to the weather should be thoroughly rid of very dirty, which indeed is not a problem because afterwards eliminates the formerly very annoying polishing with chamois leather or microfiber cloth. At first, he is also very good in the hand - with many windows it is however increasingly difficult. But then we can grow well with two hands and lead him. The first time I cleaned 6 window with a filling, two patio doors. Smaller windows I have the puck out according to size just from left to right and vice versa, which works well. The purchase price, however, I find a little high with 249 euros and the spare parts and the cleaning concentrate are not cheap. Maintenance Vorwerk prices. If it sees fit, good care long, I am very satisfied. So makes window cleaning really fun! Is something for window cleaning muffle!