Genuine OEM BMW Acoustic Insulation Foam, part number 11128623487. This foam material is designed to reduce engine noise and vibrations, contributing to a quieter and more comfortable cabin experience for occupants. It is typically located in the engine bay, often fitted to the underside of the hood or firewall. Custom-molded to fit specific vehicle applications, ensuring optimal coverage and sound dampening. Genuine OEM insulation provides the correct density and fire-retardant properties required for safety and effectiveness.