Don’t bother with this. If you want what this promises. there are better made options – which cost more, but are not awful – in retails stores that sell Beds, Baths and proBEblY-Other-thiNgsD.
The primary problem with it is the very poor fit - the moving parts are not spaced where you would want them to be, so they’re REALLY uncomfortable at least and painful at worst. I regret my purchase.
Not built to last, which can be verified easily by unzipping it to see the tracks that the moving parts use to maintain electrical connection for the motor. Pretty sure it’ll grind right through that.