http://www.northerntool.com/shop/tools/product_200433447_200433447&issearch=713200 The Fuel Doctor FD-47 increases a vehicle's miles per gallon (MPG) through power conditioning of the vehicle's electronic control unit (ECU), fuel injection and engine timing equipment to operate more efficiently. When the vehicle's engine runs more efficiently, it will require less fuel, produce more power and have reduced exhaust emissions (reduced CO2). As a vehicle matures, its power systems tend to generate and experience more electrical noise or electrical interference. This noise can have many detrimental effects on vehicle systems, decreasing efficiency. The FD-47 is easy to install simply plug it into the 12V power port and the power conditioning qualities of the FD-47 help to reduce and remove noise, restoring vehicle efficiency. FD-47 cannot be used on hybrids or electrical vehicles. What retards are they selling this to?