Licensed Kickstart 3.1 for Amiga 4000 Desktop. Compatible with Amiga 4000D only. It is a Commodore Edition Kickstart. You need them to use Workbench 3.1 in your Amiga.
You will get two 40 PIN modules. You should repleace your old modules with new ones. It is a specified ROM with labels from Cloanto with unique serial number.