The SOS Sub Surface Carpet Extraction Tool allows for targeted airflow to the pad and backing beneath the carpet to extract contaminants, odors, and liquids, such as pet urine, feces, vomit, and more. The SOS Tool works in conjunction with our Smiley Paws Urine, Stain, and Odor Remover to create the StainOut System. The SOS Tool uses a process called sub-surface extraction. Sub Surface Extraction is used by professional carpet cleaners to thoroughly remove contaminants, liquids, and odors that have soaked into carpet padding and upholstery. Short of removing carpet, sub surface extraction is the best method for flushing out the true cause of odors and reappearing spots.