It took us some time to find a way to deliver a boost/vacuum hose that lives up to our high quality requirements. Most aftermarket silicone boost/vacuum hose that you can buy is too thin to carry vacuum! It will collapse under vacuum causing a wide array of problems, including high emissions, incorrect gauge readings, poor gas mileage, and possibly even engine stalling. Finally, we are able to deliver this super high quality silicone boost/vacuum hose with extra-thick walls, providing increased resistance to collapsing under vacuum.