1.high accuracy, 2.speed and friction(no identation marks, 3.no flaws, good registration our ... in different qualities of film, photo-paper2, High accuracy, speeed and friction( no need indentation marks, no flaws, good registration3, do ... paper )4, be immuned to temprature, moisture and dirty5, reduce the cost of repair and promopt efficience6, Long life Steel thorn convex roller