Penetrating bristles deep clean grout & more. Drainage slits remove water faster. Easy snap on sponge cellulose cleaning surface. Replace every 50 uses for best performance. Libman Guarantee: Libman isn't just a company. It's our family name. We take personal pride in our products and stand behind them. That's why we have been the cleaning experts since 1896. If you are not completely satisfied, simply call 877-818-3380. libman.com. Facebook. Twitter. Greensteps. Family made in the USA since 1896.