From what I have seen/heard, it attached to the external penis via a vacuum . None of the internal structures are grabbed with this system. Also, you can only hang a maximum of 8lbs with this setup. I seem to recall seeing a guy post about his experience with this setup, and he regretted buying it because it gave him little more than trouble.
Actually if youre serious about hanging , you need to either build a bib or buy one. See my sticky thread at the top of the hanging forum about making a modified BIBhanger . Simple to do and will work a lot better, because unlike something like the TLC "tugger", youre pulling on the internal structures 100% of the time instead of 80% skin. The tugger is designed mainly around forskin restoration.
PLUS, you can build the home made bibs for only around $10. They can support all the weight you would ever need to hang (20lbs++).