Best One Out There
I've tried about 8 of these wedge seats with the cut out area.  The cut out area never seems to feel right.  I bought this a while ago for a Sacro-Illiac issue and it was great.  Recently I had a horrible Sciatic Nerve injury in my lower back and had awful pain in my butt and left leg.  This seat was a life saver for hard seats.  I even brought it to church while my injury was pretty tender and it allowed me to sit in the hard seats at church for two hours.  Thank goodness for this seat.  The small wedge part makes it doable for most chairs.
Rating: 5 stars