The window cleaning robot RCW 4 replaces the manual cleaning of large and hard-to-reach windows, ensuring a clear view. Thanks to its powerful vacuum technology, it guarantees a secure grip on all smooth surfaces, including mirrors and shower cabins. Even frameless glass surfaces are quickly and reliably cleaned through systematic navigation with 4 sensors for frame, object, and edge detection. For optimal results, the microfiber cloth is continuously and precisely moistened with cleaning solution by 6 pump-operated spray nozzles. This direct moistening prevents dripping and wind displacement. Four automatic cleaning modes and a manual mode are available depending on the level of dirt and can be conveniently controlled via remote control. LED signals and voice output provide precise information about the device status, such as when the cleaning solution tank is empty. The included window cleaning solution RM 503 effectively removes dirt, dries streak-free, and allows rain to bead off faster for long-lasting cleanliness. Even in the event of a power failure, the RCW 4 remains securely attached to the glass thanks to its emergency battery and safety rope.