Kärcher, quality and practical things. This surface cleaner exceeded my expectations real. On our balcony we have tiles and partly but violent verdigris. Alone with this cleaner and cold water on the Kärcher high-pressure cleaner, I get easily clean my balcony without the addition of detergents 100%. Have so far only tried to smooth surfaces, because I think that the hard surface cleaner could possibly go broke in concrete slabs. But the system is simple: a rotating water jet by nozzle cleans the floor and the mechanical advantage through the brush, it squirts water next to no out when it travels grade. For uneven surfaces natural water would splash out. I'm very satisfied, friends of mine have already bought.