GS marking: The GS mark ("Tested Safety") is a state-regulated but voluntary test mark in Germa-ny in the Product Safety Act (ProdSG), which is only used for ready-to-use products, i.e. not for grinding wheels. Grinding wheels are usually used with a machine and therefore cannot be marked with GS. CE marking: Abrasive products as accessory tools according to the Machinery Directive do not fall under the requirements of CE marking and therefore cannot be marked with CE. ISO marking: ISO certification is intended for companies, institutions and authorities, but not for the products that are manufactured. Therefore, abrasive products cannot be marked with ISO.