Worked Ok
Well, it did keep me from rolling onto my back, but I did not use it per the horrible directions.  Directions are minimal.  It has a picture showing strap to chest not waist, but doesn't say what the benefit of chest vs waist is.  The strap is awful!  It is rigid and bulky and feels like sleeping on rocks for the most part.  First,  I am a woman and strapping this across my breasts was not appealing or comfortable.  I tried just below and the strap hurt my ribs, so I went with the obvious choice and strapped it to my waist (as directions said not to do).  Worked fine strapped around waist.  I was unable to roll to my back.  I will be changing out the straps as they are uncomfortable.  I want straps that have some flex and are thinner.  I don't understand how this would facilitate good breathing strapped tightly around the chest.  This was the only product I could find to keep me from rolling over, so I am grateful it was available.  However, it could be more comfortable with better straps.  The directions are probably vague to avoid making claims so the FDA doesn't shut this down, but a bit about what the benefit of chest vs waist would have been nice especially as it is uncomfortable as directed.  It is also darn hard to inflate.
Rating: 3 stars