1x4 Sensor-Cleaner wet + dry in full size. The correct amount of Wet Foam is essential for safe application. The special surface of the Dry Sweeper ensures streak-free cleaning. Features of the Wet Foam: grease-dissolving, non-toxic, non-flammable, no risk of overdosing, no overflowing liquid, removes grease stains, safe to use. The Dry Sweeper is used immediately after the Wet Foam to lift away the dissolved dirt. The silk-derived cloth used is secured with a special technique.