The Hydra Epoxy Grout Sponge goes through an extra manufacturing process called hydrophilization that gives it tremendous water-holding capacity. The Hydra Epoxy Sponge works as well as natural sponges but at considerably lower costs. Hydra Epoxy Sponge will wash out clean, dry soft and pliable, and are uniform in size and quality. • Pre-wipes and rinses faster • Round corners • Polishing >> Made with polyester sponge material which provides superior strength and a cell structure that wipes and rinses excess grout faster. Sponge is shaped with rounded edges that are designed to minimize digging out or scoring of grout lines.” Size 7×5-1/4x2in (180X130X50mm)