They have been discussed before - here are some links for your consideration . . . . http://talk.newagtalk.com/forums/thread-view.asp?tid=110432&posts=23&highlight=sleep%20number%20bed&highlightmode=1#M788550
http://talk.newagtalk.com/forums/thread-view.asp?tid=8603&posts=18&highlight=sleep%20number%20bed&highlightmode=1#M55434