Game description from the publisher:

The Descent: Journeys in the Dark - Second Edition Conversion Kit includes everything you need to transfer your first edition heroes and monsters to Descent: Second Edition.

With Second Edition-compatible cards for every monster and hero ever produced (including promotional heroes!), this convenient conversion kit is an indispensable tool. So whether you want to bring your extensive Descent collection with you on new adventures, or you've got a favorite hero that you choose every time, you're covered.