Grinding wheel dressers are tools to sharpen grinding wheel surfaces to restore sharpness. The grinding wheel becomes clogged as it is used and sharpness declines, and dressing is work to remove abrasive grain clogging the grinding wheel and cutting chips clogging the pores. Periodic dressing helps make the grinding wheel last longer. Diamond is often used for the tip and surface used for polishing the grinding wheel, and a wide range of items such as wood and plastic products in addition to grinding wheels can be polished using the hardness diamonds are known most for. They can be used as files for finishing too. There are various shapes from handheld types to types installed on machines, and the type must be selected according to the application it is used for.