It is not a workout equipment as such, unless you consider a book, an equipment.
I just received the latest book by Stuart McRobert: Build Muscle, Lose Fat, Look Great
I have several strength training books, I think, this one, will be my last, for a long long time.
When I was browsing thru the pages, yesterday, my jaw hit the floor, WOW, My GOD, Goosh!, Youpii.
640 pages, jam packed of all the informations that you could ever ask, unbelievable.
Definitely worth a look.
This one, I'm sure, I will read it, cover to cover, maybe more than once.