Over the past 20 years I have spent a lot of time on the idea and had test samples from an ex NASA engineer who researched this for a long time for NASA. He and many other institutions confirm that it works in principle (the molecular harmonising resulting in a quicker combustion), but the problem is that the application is very difficult to realise in practical terms.
Without going into boring details I am very skeptical that the way the unit is produced has got the impact this technology could.
No disrespect to the people who gave their testimony of savings, but they are scientifically not to be taken into account as many factors are not considered when testing. Such testimony is devalued by the conscious use of the unit, which hasn't happened before to mention only on variable.
My personal opinion is to stay away from these ideas before nobody comes up with relevant instructions, which are quite a bit more than what is there on ebay.