The product is an Engine Core Plug-Expansion Plug, specifically the Expand-Tite model from Dorman/AutoGrade, with the manufacturer part number 02523. This plug is designed to fit into engine cores to prevent leaks and maintain proper pressure within the engine. It is a single quantity item and has a SKU of MM:02523. This engine core plug offers a reliable solution for sealing engine cores and is a quality product from Dorman/AutoGrade.