9 inch Polyester Paint Roller Description Using high denser woven polyester fabric with long-nap For use water-based latex and stains. 9 inch rollers are the most commonly used size. Great paint pickup and release for semi-smooth to extra-rough surfaces Thermofused to polypropylene core that fabric bonded to the core firmly Diameter Core: 1½"(38mm) and1¾"(44mm) http://www.cohwabrush.com/polyester-paint-roller/9-inch-polyester-paint-roller.html