I found a Therapedic "The Reading Wedge" for about $52 and change, including tax.
The dimensions area 18" * 36 " * 12" (45 cm * 91 cm * 30 cm)
Micro Gel Fiber Fill
Machine Washable Zippered Knit Cover
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The pillow is long and somewhat floppy. That made it a bit awkward for me to maneuver the pillow to where I wanted it - I'm not very tall, so I don't have the leverage, plus my back isn't stellar.
I tried lying supine partially on the pillow; that wasn't comfortable.
Getting on my left side with the pillow as a bolster behind my back was more comfortable for me. (The left side is recommended if you have GERD, too.)
And this morning's AHI was one of my lowest (0.49). If I can make that repeatable on a nightly basis, it may work for me.
Note: I'm an epidemiologist, not a medical provider.