i work at an orthopedic hospital and I purchased this guide a few months ago. I can tell you this thing is great!!! I do all my blocks with this guide right in front of me and it gives me the best info. I routinely use it for infraclvicular and for poplietal bec its hard for me to remember the landmarks for them.
For my residents, I tell them routinely that if they just memorize the info on these cards, they'll be set for the boards!! I'm not kidding, EVERYTHING u need to know about regional anesthesia is in these cards!