The Purdy 144602183 18" Paint Roller Cover is a high-quality painting accessory made of nylon and polyester materials. It features a 1/2" nap size and is designed for use with water-based and oil-based paints. The roller cover is semi-smooth in texture and compatible with a standard roller frame style cage. With an overall length of 18 inches and a core diameter of 1 1/2 inches, this roller cover is perfect for painting on various surfaces like concrete, drywall, and masonry. The product also comes with a 1-year manufacturer warranty for added peace of mind.