I got the smaller one by Synergy Systems. I have a friend in Vegas that uses the larger one for his allergies and they are completely gone. I use mine to make olive oil, water, for better health in general, and have also used it on a really bad foot infection (which is now gone!). The guy who sells these will deal on the price if you email him. I have just read on his auction that he now offers a variable output on the machines. They have glass tubes inside (not the cheap plastic found in the chinese made ones, that breaks down over time and then enters our systems, which can make us worse off in the long run). It came with a bubbler stone and silicone tubing. You can only use an oxygen source as this is medical grade. I very highly recommend this machine over any of the cheapy ones out there. Good luck!