Be pressure 85.403.007 20″ heavy duty composite whirl-a-way cleans flat surfaces, walls and even rooftops 3 times faster than water brooms. flat surface cleaners are able to clean 400 sq. Ft. In almost 10 minutes. 4,000 psi rotary head withstands up to 180f. Offers a maximum flow rate of 8.0 gpm. Features 2 welded steel rotary bars with zero wall clearance for efficient cleaning.