SCE Pro Copper Exhaust Gaskets feature an Embossed O-Ring around the exhaust port. Perfect for everything from street performance to towing and RV's, this design increases sealing pressure to give you a tight, permanent, leak proof seal even on irregular surfaces. SCE Gaskets invented and introduced the embossed copper exhaust gasket back in 1995; SCE manufacture gaskets for more applications than all others combined.  (Sold as a Pair)