Knuckle Buster™ microfiber Velcro wet flat mop provides a simple superior cleaning experience. Our microfiber mop is filled with microfiber. It has no inner foam layer which means it has greater absorbency and durability. Our microfiber mop can be washed many times; some customers are getting over 130 washes. It can be used on any hard surface and leaves no streaks or residue.