The Wagner 9 in. x 3/8 in. Polyester Replacement Power Roller Cover features high-quality polyester to provide excellent coverage and an immaculate finish.Internally-fed roller covers distribute paint evenly across the roller, creating a smooth, professional paint finish on your walls. With a 3/8 in. nap, this roller cover is perfect for walls with minimal texture. A high absorbency nap material holds a large volume of paint for continuous rolling.