I dunno,Yours must be 2nd or 3rd gen.....
How large are the "sandbag" areas as you measure the criss-crossing seams?
The gen 1 we have are like 7-8" on a side or maybe a bit larger.
They don’t seem very big. I got mine in May because of sleep problems and it works is all I know.
My only issue is it can be hard to adjust and I wish it was 6 inches longer.