ADD W1's Billet Aluminum HKS Blow off Valve Adapter allow you to install HKS BOV onto your Hyundai Elantra Sport and other Hyundai/ KIA vehicles without any welding or modifications. Machined groove on the bottom of the flanges utilizes your OEM o-ring gasket. We include new o-ring gaskets for the HKS BOV and stainless steel install hardware to ensure your kit will continue to look good for years.