There is the Extraction Module that pulls out items and lets anything back into the inventory, and there is the Blocking Extraction Module that pulls out items and lets nothing back into the inventory. But with the common occurrence of overflow and backstuffing, it would be good to have a third extractor that only allows items that already exist in the inventory to return to it.

The same thing can be simulated manually by mixing a Multi Module, Extraction Module, and Filter Module with the filter set as custom with "Iron" or whatever the material or materials in the inventory are. But it would be much easier to have a single module instead of three and no requirement to figure out the correct filter string and type it in.

It would probably be best to code this module so that it never extracts the last of a particular item.

This module would work particularly well with the Crafter Module.