The BE-Fuelsaver ® is a metal stick, only a couple of centimetres long, made out of stainless steel. It is placed in a tank of a car or it can also be put in the fuel line. It reduces the fuel consumption significantly while also lowering the pollution (up to 90%) and improving the engine power. Please read the product description to find out which size is needed. For first time buyers it comes with a 90 day money back guarantee. On top of that there is also a 10-year function warranty!