Plato® sponge Model CS-17/625 are manufactured with pure cellulose (a wood derivative) which has the ability to absorb many times its weightin water. Also resistant to abrasion and tearing forces that occur during the tip wiping process. Cellular structure is designed to expand when wet, and retain water for long periods of time. Meets ANSI (J-STD-001B) for low sulphur content and fine porosity. Unlike other SYNTHETIC sponges which are not recommended for use as tip cleaning sponges.Many cheap household type sponges are manufactured with man-made fibers and materials. These sponges contain colorings, sizings, plasticizers, stiffeners, and other Contaminants which will promote detinning and shorter tip life. Use only Plato pure cellulose sponges to aid in keeping your solder tips clean and to extend tip life.Sheet Size is 8.5X16.5 Inch and Thickness when in water is 1 Inch. Plato sponge are low on price and friendly to your soldering tip.