inserts
n. countable B2 Upper Intermediate US //ˈɪnˌsɝts// in·serts
n. extra parts or pieces of material that you put inside something else to make it work better or fit correctly.
n. components or materials designed to be placed within a larger structure to provide support, protection, or specific functionality.
I bought soft foam inserts for my new shoes.
The magazine includes several advertising inserts that fall out when you open the pages.
Engineers specified high-strength carbide inserts for the cutting tools to ensure the machinery could withstand the friction of high-speed manufacturing.
Usage
Often used in the plural when referring to shoe padding or printed marketing materials.