My husband and I had purchased a new hybrid bed one year ago.  It is a high quality big brand name bed, and it was expensive; however, the medium firm model was just too firm for me, as I am a side sleeper and medium build (150 lbs).  We tried another topper that was 2” thick, and it was just too squishy. It sank and hurt my neck and back every morning.  This was the only place I could find something thinner.  The topper came and inflated to its size in just a couple of minutes.  Minimal smell; you can only really smell it if you stick your nose in it.  I let it air out for about 12 hours and then put it on my bed.  What a HUGE difference just one inches makes!  I woke up with no pain and didn’t wake up in the middle of the night with sore shoulders.  Love this!!!