I got mine from Costco. Don't use much as my acid reflux is under control....but if I eat late or feel something coming on I pull it out.
You have to sleep on your back. It works great as it forces acid to stay in the stomach.....worst part is I'm also a side sleeper so I wake up middle of the night and turn on my side and it is really uncomfortable as it is not made for that. So I have to kinda wake up -fling it to the other side of the bed or floor and use a traditional pillow. But, at that point I am in the clear in terms of acid reflux.
RIP Bucky - 7/25/1943 - 1/19/2013