The 5-3/4" x 2-3/4" x 2-3/4" Deluxe Series Large Pumice Stone is the ultimate tool for effortless pool maintenance. It is designed to remove hard water stains, rust stains, and mineral and mildew stains from pool tiles, surfaces, and pool floors. Perfect for hard to reach spots and built-up grime, this natural stone is safe to use on most pool materials, ensuring your pool stays in pristine condition without causing scratches.