That site lists some non-factory approved accessories that are NOT recommended by the inventor Dr. Back nor Dr. Jeff Sutherland. Also no other dealer supplies (and pays for) free training from Dr. Jeff Sutherland. If you get a BPA you want to have the best education ever, and that's going to come from Dr. Jeffery Sutherland & Dr. Back. They have developed devices (accessories ie.) many times more powerful then non-factory approved devices that it’s not funny for those who want the best that is.
As far as the Altered States is concerned they do not listen to the inventor and have put up some really not-factory approved comments and are more of a five and dime of goodies as you notice with little focus on any one or three things. The BPA is a Scalar wave device but more important it is the only safe device available that cannot be used to send negative patterns to anyone and it senses when a subject has had enough balancing and turns off all automatically.
I personally have been a research subject involved on the recipient end of this technology, research, and expiramentation for nearly 2 year now, with some trials and errors, and overall resounding success (truly amazing). It's quite amazing that a former U.S. National Institutes of Health member and also a another scientist (formerly working on U.S. Military Satellite tech) have come together and in innovating and developing these technologies and devices for healing research and Science to the world at large. It's a great way not to have to be "wired" in to a machine, and get "transmissions" of specific frequencies targetting you while you go globetrotting, fishing, hunting, or whatever you find is your fancy in the world. Without a doubt, it's cutting edge technology, and show promise for the future of energy medicine *research*. Some of us, however, are enjoying the great moment of "now", and all the inherent benefits and learning curves of that.