A rear roller is a simple addition to classic lawn mowers that makes an incredible difference in results. It is used to create that beautiful striped finish on your lawn. In fact, the roller makes lighter and darker stripes on your grass, like those you see on sports events, so your lawn ends up looking very stylish. It creates this effect by a simple weight principle. Namely, the rollers are usually filled with sand or water, so they are pretty heavy, and the mass pressed on the grass creates the effect we explained. Usually, rollers are made of either plastic or metal.