All products are marked with a serial number. This makes it possible to retrace completely the production chain and quality checks.
![Example metal model plate metal expansion joints by HKS Example of a HKS metal model plate which is attached to metal expansion joints](assets/images/3/example-metal-model-plate-metal-expansion-joints-ecbb9554.jpg)
If the customer so wishes, the products can be provided with a metal I.D. plate showing for example the serial number, nominal width, pressure level, year of manufacture, customer part number or customer order number.