Hot fuel results in less HP, increased fuel pump stress, and the increased risk of vapor lock. The DEI slip-on fuel tank cover is made from a 2mm felt-backed Mylar material and is capable of reflecting up to 90% of the sun’s heat. This helps prevent the fuel in the tank from baking in the sun between green flags. Simply cinch the draw string and your bikes fuel will stay nice and cool between races. Elastic edges ensure a snug fit, no matter what brand you ride. Fast on & off, perfect for the paddock. Reflects heat from the sun .Helps prevent vapor lock. A must for hot sunny days. One size fits all. Won’t scratch or harm tank. Keeps hot sun off tank & keeps fuel cool.