Well-used genuine Prusa double-sided textured PEI powder-coated spring steel sheets as shown here: https://www.prusa3d.com/product/double-sided-textured-pei-powder-coated-spring-steel-sheet/

Sheets are functional, but have unevenly worn areas that will leave behind marks on the bottom of future prints. Some sheets may be missing chunks of PEI. They are no longer usable for our print farm, but may be usable for your needs and we'd rather keep them out of landfills for as long as possible.