Most of those gizmos and gadgets don't really work.It looks like this one is another of those inline fuel(ionizers,stabelizers,molecular structure of fuel improvers).They pop up every few years,and they're all just magnets.Whenthey do work,what's actually going on is the magnet is attracting the rust particals in the fuel system and causing a fuel restriction.Which leads to you'r engine running leaner.Slightly leaner fuel mixture can increase you'r mileage and power.But you'll burn you'r exhaust valves out and cause premature wear on the engine.Vapor carburators actually do work and give unbelievable fuel mileage.100-200 and more miles per gallon on big full sized cars.But you need pure,raw gasoline for them to work long term.I believe all modern gasoline has oil that has been molecularly cracked to create more gasoline mixed in.You try vaporizing the cracked oil,and you get a tar residue left over.These carburators worked great back in the 1920's and 30's when you bought raw gasoline with no addatives or fuel cracking to increase gasoline production.And even though they did really work back then,the car makers never installed them.Yes there still are super high effiency fuel systems around that do work with modern fuel.And the car manufacturers know about them,because they own the patents by hostile acquisition.THIS is not an urban legend.They could be building 300 mpg cars today.I don't know why they don't.But I personally know of at least two carburator designs belonging to one of Americas big three auto makers that are real.And the inventor of one of them who I used to know personally was threatened to sell his patent to them or he and his family would disapear.Yes he sold to them,but he doesn't dare ever tell anyone about his design.I knew about it before the patent.