B. Secure network components, B.6 Physical devices question

matai

Hey, I'm helping out a buddy with exam prep. I have a question about:

Domain 4, Communication and Network Security
Key Area of Knowledge B. Secure network components
Sub Key Area of Knowledge B.6 Physical devices

Does anybody know what's included with B.6 Physical devices? The official study guide doesn't have anything for this subject. It's listed in the contents, but no sub-section. I've found this with a few other subjects, very frustrating.

Thanks!