OEM grade” refers to products manufactured by an Original Equipment Manufacturer, meaning a company that produces parts or goods that are then sold to another company, who then rebrands and sells them under their own name. Essentially, the OEM makes the product, but the branding and marketing are handled by a different company. In the context of products like shoes, “OEM grade” might imply a level of quality comparable to the original product, but without the official brand name or packaging.