I am very disappointed with the Xtreme Scheibenklar NanoPro. It leaves no nano effect. I have tested several times at several different glass surfaces and other than a cleaning effect did not remain on. I had bought in the summer for the windscreen washer system of my car Sonax Xtreme Scheibenreiniger NanoPro and was very pleased with this. A same effect I had hoped for from the spray. None. For a simple glass cleaning effect of this product is too expensive! Since a glass cleaner ranges from discounters for 1.99 euros.