Best-in-Class Microfiber delivers superior cleaning performance and durability. * Vertical polypropylene scrubber stripes remove stubborn spots and clean into tile grout lines. * Dense "Ultra-Fine" quality fiber removes more dust, dirt and bacteria than conventional cleaning products. * Advanced hook-and-loop backing... holds-up under harsh laundering conditions and attaches pads more securely. * Durable pad construction... third party tested tough... withstands more than 300 launderings. * Double finished edges retain pad shape with use over time.