Graphic Blue-Runner dampener cover is made of specially formulated fibers to insure maximum performance and durability. This list free, pattern free material lasts 4 to 10 times longer than cotton. It's multidirectional manufacturing makes adjustment to the roller a breeze. Specially treated fibers for optimal water absorbancy. Fits rollers 4 3/4" (121mm), 5" (127mm) and 5 1/4" (133mm) in diameter.