Where can I find ready off-the-shelf assessment centers exercices. Preferably a book or PDFs. No consulting products?

You can find ready off-the-shelf assessment center exercises in books like "Assessment Center Handbook for Hiring Managers and Candidates" by T. L. H. McCarthy, which provides a variety of exercises and assessments. Additionally, the book "The Complete Guide to Assessment Centers" by Robert Edenborough offers comprehensive materials. For PDFs, websites like the Society for Industrial and Organizational Psychology (SIOP) may have resources available for download.